Grease Dance
50 Achievements
PS3
Hit It
Flatten 3 bumps in a row during Panel Beating in Greaser's Garage without causing any more arising
27.5%
How to unlock the Hit It achievement in Grease Dance - Definitive Guide
Beanpotter
TrueAchievements
TrueAchievements
Hover your hammer over a bump and a timing bar will appear. Simply strike down with your arm to flatten the bump whilst the indicator is in the white area. The smaller bumps have a bigger margin of error so go for those first.
leptonic
You need to play the first section in this minigame: Hammering. Here, you need to move the hammer to any dent in the car and press 
moving the controller back and forward to fix it.
So for this trophy, you need to press the button to fix 3 bumps in a row. This means press it when they are in the white area, not in the yellow one netting you 10,000 points. In fact, this is really easy and you should pop this trophy in your first try.