I know of two yards where they keep vehicles etc and they are huge ,storing thousands of them.
(1)Take the road from alwakrah to wukair.Go straight until few kms before it joins to massaeid-salwa road.Keep an eye on your right hand side till you see this massive car dump yard .Alternatively you can go on salwa road and take massaeid road to the left.On salwa -mas saeid road turn left for wukair ,yard should be on your left had side.
(2)From massaeid to wakrah take a right turn opposite sealine petrol sttn.This asphalted road will take you straight to another massive dump yard .
Good luck.