The trucks cost 60 bottle caps because 10 x 6 = <<10*6=60>>60
He has 40 bottle caps left because 100 - 60 = <<100-60=40>>40
He spends 30 bottle caps on cars because 40 x .75 = <<40*.75=30>>30
He gets 6 cars with this because 30 / 5 = <<30/5=6>>6
He gets 16 vehicles in total because 10 + 6 = <<10+6=16>>16
#### 16