William spends 4 + 7 + 4 + 9 = <<4+7+4+9=24>>24 minutes washing a normal car.
He washed 2 normal cars, so he spent 24 * 2 = <<24*2=48>>48 minutes on the normal cars.
He took twice as long as one car for the SUV, so he took 24 * 2 = <<24*2=48>>48 minutes on the SUV.
Thus, William spent 48 + 48 = <<48+48=96>>96 minutes washing all the vehicles.
#### 96