how do i get new car for midnight club la?

 how do i get new car for midnight club la?
 
i got a white beginner car and i want to get a new car. and why my boost meter take so long to build up? its like they going backwar.d.. their older mc got often boost but this so long.
 

With all due respect, I really don't see what could possibly be difficult about obtaining a new car.  
 
Accumulate a good amount of money by winning races (actually, even placing lower than 1rst gives you money, just not as much as you would have gotten had you won) and go to the vehicle showroom in your garage. You will be able to purchase cars there.  
 
Another way to obtain a new car is to find a race in which the reward for winning is a car.