when i lived in west michigan, i volunteered time to crew for an ALMS/Grand Am team. the 30 months i offered help, they used 3 different cars to field each year: Ferarri 360s, Porsche GT3 and the third year, they moved to Saleen S7s. For the most part, the owner financed the team himself. his company made the core of it's money hydroforming frames for popular SUVs. it wasn't a top echelon team, but we did ok. It had a lot of volunteers who sacrificed their vacation time (like me) to work for the team. There were paid crew members and technicians, but I was afforded plane tickets and stipends for hotels and food. Generally, though, I work about 12-15hours a day on these race weekends. i had to wear a uniform, had to keep team communications on me at all times and do what i was told. i did everything from inventory equipment for transport to catalog tires for each planned scenario to polishing the painted carbon fiber body work. it was hard work, but it was a lot of fun as you ride high on the enthusiasm of the team, the fans watching you and the owner (who was a stern, but genuinely nice man).
at that level, the teams are really a marketing tool. it a part of a business and you represent that business through that team. they DON'T make money, typically, but it's like advertising and perception. you get a group of organized people, passionate about the sport, and the car have the sponsors or company's logo on it and fans andthe general public associate the team's behavior and results on the track with the sponspr and/or company.
i got on this team through two contacts. first the HR director of the company i worked for was the wife of the crew chief. she would strike up conversations with us at work because you can SEE who is an enthusiast by stuff people have in their office. she invited me and two coworkers to tour the team's garage and to meet her husband. we all were HUGE car guys invovlver in some form of racing. we were hooked. also, a relative of mine owned a body shop and did all the paint work for the team's cars.
it was an awesome experience.