Not exactly a mission but a test to see if you are good enough to start actually working for these guys. Even though it is the first mission in the game it is still unbelievably difficult but try completing it in training first before trying it for real. Anyway if you are still finding it hard then follow these simple steps-
Burnout at the start, pretty easy
Yank the handbrake at the end of the garage and straighten yourself up for the slalom
Take the slalom slowly. Too much power and you'll lose more time by sliding all over the shop. Also remember that you can only afford 3 knocks or the tester (and car owner) will chuck you out for wrecking his precious motor.
Once you have got slalom checked off then go for the lap. It doesn't actually matter what order the tricks are pulled in
Now do the remaining stunts, 180, 360, reverse 180, speed and brake test, in what ever order you like.
It may take you several attempts to do but don't worry as you soon will be able to complete it in 24 secs like me!