They are easily distinguished from other buildings by their giant signs with blue lights and distinct building design made for drive-throughs. They will appear as a green open-end wrench on the mini-map. The repair shops are all owned by a fictional company called "Knocking Brothers".
These repair shops combine the ability to repair, repaint and refill nitrous of the player's car once they have driven though it. This allows any visual damage and burst tyres to be repaired.
Passing through a Repair Shop during the cooldown phase of a pursuit will reduce the player's heat by a single level per visit.
It only serves to repair damage and refill nitrous on a player's car in multiplayer as repainting the vehicle is only available through unlockable paint schemes.