This glitch shows how particular cars in Gridlock can be mounted upon. My friend taught me this glitch a while back, using the Method xPandDxProductionsx uses (at the bottom of this page). However, I was Gearsin' with this dude named Destoction and we each found our own ways to do it, achieving the same effect as the same effect as xPandDxProductionsx, only alot simpler. Here are all the methods...
Destroction's Method
1) Go to the car (in the video at bottom) with any gun
2) Get right behind the car in the middle of it
3) Press forward (on left analog) and A at the same time, very quicky, you should now be mounted.
My Method (I do not claim ownage to this becasue I'm sure it has been found before in the past)
1) Go to the car (in the video at bottom) with any gun except the lancer
2) Get right behind the car in the middle of it
3) Tap B and A simoultaneously, you'll now be mounted on the car.
xPandDxProductionsx Method and Video
And here is the tutorial...
1) Go to the boomshot on gridlock.
2) If you face the sniper tower, go to the left of the boomshot where you will see to cars in the shape of and L put together.
3) Get on the one closest to the boom and have to lancer out.
4) Get into cover on it and hit B then A then B until you pop up in cover on the car and then hit B and walk forward and your on the cars.