Can I Borrow Someone's Charger? - 15 Gamerscore
R.C. Pro-Am II: Complete 100 laps over time.
The fastest way to get this achievement is to start a race and right before you finish your first lap make a save file. After a save file is created just finish the lap and reload your save file and repeat. I would recommend doing this achievement last and snap open your achievements to make sure that it is keeping track of your laps.
Hopes this helps, pm me or comment if you have any questions or anything to add to the solution. If you give me a negative vote please comment or pm why so i can fix it.
Good Luck and Happy Hunting.