DiRT

Just do a single race on Windy Point Hill Climb in the Tacuma, Escudo or one of the other crazy unlimited cars. There's a huge straight at the start that you can get up to 140mph+. The achieve unlocks as soon as you hit 136 mph, you don't have to finish the race.

I did this on the Valeo European Group B Classic Rallycross event in Tier 4

Buy the Lancia Delta S4 for £300.000
You will reach 135MPH on the straightaway after the last corner, if not you will almost definately reach it on the 2nd race in the same event.

The 2nd race is easier to reach 135MPH on as the straightaway after the last corner is longer.

I did this myself on both races.