Alot of the car numbers, 'teams' have different owners, often different to the owner of the whole organisation, why this is I'm not sure, one interesting one is Jeff Gordon is owner of #48, while he doesn't own #24
http://www.jayski.com/stats/2007/sta...2007owners.htm
I'll try to do some more research into it.... could possibly be so they can enter many cars in one race, I think the full time limit is 4, Roush had 6 cars in a race last year (Kenseth, Edwards, Biffle, Martin, Ragan and Kleuver)
oh and to answer you question about how those cars with so much power accelerate so slowly at Daytona, it's all because of the restrictor plate, it basically halfs the power available.