how does buying a new car work?

[mqzy]

im 18 and just got my license and thought, just for the fun of it to go down to a dealership to test drive a new car. i could play the "i have a rich father" act and wear some really expensive clothes and be like "excuse me, im in the market for a new car. no more than $40k....." and so on.

if i walk in there asking to test drive a new car, what will they do? i dont want them to be doing all background checks on me and looking into my bank accounts and what not.