Each car in the garage has 4 wheels, for a total of 4*2=<<4*2=8>>8 wheels.
The riding lawnmower has 4 wheels, bringing the total up to 8+4=12 wheels.
The bicycles have 2 wheels each and there are 3 of them, for 3*2=6 wheels, bringing the total to 12+6= 18.
The tricycle has 3 wheels, and the unicycle has 1 wheel, bringing the total up to 18+1+3= 22 wheels
#### 22