Jaden had a total of 14 cars + 28 cars = <<14+28=42>>42 cars after buying from the toy store.
His total then increased to 42 cars + 12 cars = <<42+12=54>>54 cars on his birthday.
Jaden then had 54 cars - 8 cars = <<54-8=46>>46 cars after giving 8 to his sister.
Finally after giving his friend, Vinnie, a few cars Jaden had 46 cars - 3 cars = <<46-3=43>>43 cars left.
#### 43