The first segment is by far the largest, accounting for more than $190 billion in sales in 2004. The automotive aftermarket includes do-it-yourself (D-I-Y) parts and accessories, which generated $35.4 billion in sales in 2004; service and repair, $136.9 billion; and tires, $17.8 billion.

Among the other broad segments of the U.S. motor vehicle aftermarket in 2004, heavy duty accounted for $63 billion in sales; paint and body equipment for $3.1 billion; tools and equipment for $8.1 billion; and trim for $5.6 billion.

Industry participants are optimistic about the future for their business in virtually all segments. In the paint and body equipment segment, for example, 92% of those surveyed by AAIA said they expected an increase in their sales over the coming 12 months.

"We found it interesting that while the majority of parts used by both independent and dealership body shops for collision is original equipment (OE) parts, the use of non-OE parts is becoming more prevalent," Schmatz said. "Additionally, more than half of collision repair shops surveyed believe that the quality of non-OE body parts is improving."

Today's automotive aftermarket is an increasingly complex and competitive business that is undergoing profound change. Rapid industry consolidation over the past decade has left fewer market players. At the same time, advances in manufacturing have resulted in higher-quality parts for new vehicles, which means that cars break down less often and have longer service intervals.

Those very same factors are creating strong business opportunities for entrepreneurs who are willing to make the necessary investment-both financial and personal-to create and grow a successful company.

While the automotive sector is also getting a boost from many sources, two important ones are the increasingly attractive value equation behind automotive repair services and robust growth in the light truck segment of the aftermarket.

Compared with other services, auto repair is a real bargain, according to the Car Care Council (CCC), an industry group that partners with federal and state governments to support vehicle maintenance as a way to meet fuel economy, emissions and safety goals.

During the 1990s, the cost of hospital services rose more than 100%, and the cost of financial services jumped 90%. Automotive maintenance and repair costs, in contrast, increased just 44.5%, making auto repair the darling of the service industry, CCC says.

Automotive parts represent an even greater value equation for consumers, having risen in price just 4.2% over the past 10 years, according to the percentage changes tracked in the Consumer Price Index. That has helped to keep the D-I-Y market vibrant.

"Contrary to some industry and Wall Street naysayers, the D-I-Y segment of the automotive aftermarket is not dying," says a spokesman for AAIA. "In fact, 70% of U.S. households have someone who has personally performed vehicle maintenance or repair in the last year."

A new study commissioned by AAIA, "The Aftermarket Consumer: DIY or DIFM," reveals that 62% of D-I-Yers are doing at least as much work on their cars today as they did five years ago. The primary reason they give for doing maintenance and repairs themselves is to save money.

D-I-Yers are doing at least as much work on their cars today as they did five years ago.

Quality of service and trust were the top criteria they gave for selecting a service provider, the study found. The cost factor ranked a distant seventh.

Two segments of the industry with particular appeal in the business opportunities arena are paintless dent removal (PDR) and windshield repair.

PDR involves the removal of dings and small dents in a car's exterior, and it differs from conventional body work, which involves straightening sheet metal, filling large dents, replacing badly damaged parts, painting and even restoring a car's frame and undercarriage after an accident.

PDR is for minor damage caused by car doors, shopping carts, hail and other small impacts. The process removes the dent by gently massaging the metal back to its original shape. Repairs are performed from the back of the damaged area with the use of special tools.

The most common types of dents repaired by PDR businesses are called lows, highs and creases, with lows being the most common. A low is a depression in a car's sheet metal, usually caused by a direct perpendicular impact from an object such as a hailstone or golf ball.

Highs are the opposite of lows and are most commonly caused by closing a car's hood or trunk lid on an obstruction, such as a tool left laying across a fender well. An object bouncing around freely in the trunk of a car can also cause a high dent.

Creases result from impacts that cause some part of a car's sheet metal to fold to a point, like the crease down the front of a pair of slacks. These are considered the most difficult repairs for a PDR technician.

PDR can be a very profitable business. Repair times average about 15 minutes or less per dent, there is virtually no expense for supplies, and retail prices can range from $65 to $125 for a typical car panel with one to three dents in it.

Every new car dealer in the country uses PDR, as do conventional body shops and detail shops. The technique has been in use for more than 50 years and is 100% environmentally friendly. It is very appealing to consumers because it saves them both time and money, improves the appearance of their car and increases its value.

While just about anybody can learn to be a PDR technician, there is definitely a level of skill involved. Getting the right training, tools and ongoing support is critical, and those are the things prospective entrepreneurs should focus on when looking at business opportunities in this area.

The North American automotive glass aftermarket now totals about $1.3 billion a year and is forecast to surpass $1.6 billion by 2010, according to Frost & Sullivan, a market research firm. The biggest growth in demand for windshield repair and replacement services is coming from consumers who have purchased large sport utility vehicles (SUVs), said Mary-Beth Kellenberger, an industry analyst with Frost & Sullivan.

Other factors having a positive impact on this business segment are increases in the number of vehicles on the road, average vehicle use, property-related crimes and collision rates.

Typical clients of windshield repair businesses include commercial vehicle fleets, insurance companies, new car dealers, used car lots, car rental companies and individual consumers. Many insurance companies will pay the entire cost of a windshield repair, with no deductible, for their policyholders. Some provide the same deal on windshield replacement if the policyholder uses the services of a provider designated by the insurance company.

Profits in windshield repair are very high. The average windshield repair job costs between $45 and $100, and the repair provider's cost of supplies runs between 50 cents and $1. As with PDR business opportunities, training, equipment, supplies and ongoing support are critical considerations in choosing an automotive glass repair business opportunity.

Women represent a huge market for business owners in the aftermarket automotive industry. In fact, "It is impossible to overstate the huge impact that women have as consumers in the U.S. marketplace today," said Andrew Paradise, manager of market research at AAIA.

"In particular, female motorists are continually being recognized for their increasing buying power in the automotive aftermarket," he added, noting that 89% of the women surveyed by AAIA have at least some level of involvement in the decision-making process for their vehicle's maintenance and repair.

Paintless dent repair and windshield repair and replacement are tow very hot segements.

When asked their reasons for patronizing an independent aftermarket automotive business, 70% of women cited trust in the provider of the products or services being purchased. Cost was also a factor, with 62% mentioning the lower cost of going to an independent provider versus a car dealer.

Like most industries, the automotive aftermarket faces some challenges. One is the increasing technological sophistication of today's cars and trucks and the resources needed to repair and maintain them. Because so much of the technology is computer-based, industry groups argue that car manufacturers, which control access to the diagnostic codes for that computer technology, enjoy an unfair competitive advantage over independent repair shops.

AAIA and other organizations are fighting to change that. They have been working to support passage of legislation called the Motor Vehicle Owners' Right To Repair Act. So far, more than 30 members of Congress have signed on to support the bill.

"We want to thank these congressmen for supporting this very important piece of legislation, which not only benefits every small business owner in the automotive aftermarket, but also benefits every consumer who owns a vehicle," Schmatz said. "Every week, the Right to Repair Act seems to be picking up more and more support, and we see that continuing in the next few months."

The bill would require car companies to make available to independent businesses the same service information and tools capabilities they provide to their own dealer networks. Architects of the bill recently added new language to clarify that car company trade secrets are protected unless that information is provided to the new car dealer.