Parking is the easiest part of this game.
Here's a tip about how to beat all the 36 challenges even easier:

Automatic gear changing is a little bit awkward when you are trying to finish all the Parking areas, that's why you will have to change it to manual.

Go to Options > Control and switch "Gear Setup" to "Manual"
I recommend you to use mostly 2nd gear and you shouldn't have problem beating the 1st placed time.

NOTE: Gear UP = A | Gear Down = Z