Yes, because you insulted them. Did that occur to you? Your friends have stated pretty clearly that they aren’t interested in your fancy schmancy car.
Either find another group of friends who also have $70,000 cars, or be a little more humble…and understand that this isn’t the case for every college student. Many don’t have cars at all. Others have cars that aren’t as “prestigious” as yours.
It sounds to me like your car is more important than the people.