Using a plasma pistol and a sniper rifle, I stopped the wraith, shot out the driver, and jumped on the hood.

I melee'ed the cover for the driver's seat until it fell off... plasma pistol'ed his shields, and moved until it didn't say "Hold B to Board Enemy Wraith."

Once I was set, I switched to the sniper rifle, held B (my button to use vehicles) and sniped his head.

I was in.

I only tried this on easy, so I'm not sure how well this will help you in Firefight on some higher difficulty, but the thing definitely shoots faster, moves faster, and can take a lot of punishment.

Enjoy.