Hint: Magazine covers:

Auto Motor: 20 wins in level 5.
AutoMaxx: 16 wins in level 4.
Car Audio and Electronics: 6 wins in level 3.
Chrome und Flamen: 27 wins in level 4.
Elaborare: 3 wins in level 4.
GTI: 11 wins in level 3.
GTI : 16 wins in level 5.
Hot 4's: 18 wins in level 3.
Import Tuner: 4 wins in level 5.
Maxi Tuning: 7 wins in level 4.
Power: 32 wins in level 5.
Spoiler: 11 wins in level 4.
Sports Compact Car: 8 wins in level 2.
Street Car: 2 wins in level 3.
Street Car: 9 wins in level 5.
Street Tuner: 34 wins in level 5.
Stuff: 20 wins in level 4.
Super Street: 28 wins in level 5.
Swiss Tuner: 25 wins in level 5.
Turbo: 4 wins in level 2.