Stuntman: Ignition

For this I would say grab a boosting partner as I haven't seen anybody online in months.

Go to Multiclash and then create a Backlot Race match under the Ranked Xbox live menu option.

I would set it up with the Sport Class (faster cars) and on the Aftershock 1 or Whoopin Hollerin 1 tracks. I could get each win (3 laps total) on those tracks in 1 minute 30.

Get ten (and dont forget to help your boosting partner) and the achievement is yours.

This is not a solution so much as it is a rewrite of the achievement's current HORRID description.

'Finish 1st in 10 ranked Backlot Races'

The wins don't need to be consecutive. You also have to make sure you're going for Backlot RACES, not Backlot BATTLES (which do not count).

Had to look up xboxachievements.com for clarification. The previous solution by CasperTC is fine; it was the lack of proper achievement description that confused me.