How it works?

I'm new to the racing part of the game so i have some questions.

1)If i use some upgrade points to a car and then unlist it i get all the points spent back?
2)Driving skill increase like hunting skill? It depends on position finished?
3)Is it a little "random" who the winner is?

1-no you will get 0 points back after
2-it increases after every race it goes up fast at low stats and slows when your stats get higher
3-it was a little random before respo i think to give lower stat racers a chance at winning some times but skill always helps

Regarding 1, do upgrades stay with the car?

Upgrades stay on the car you buy them for unless you crash, then you can lose one to three upgrades.
I also think when you unlist the car you lose them all.