we dont have broken tracks in FH2... Our tanks are made out of one, solid piece of plastic. Shoot anywhere on it, and its "hitpoints" are reduced. When it reaches zero, it is morphed in to a black piece of plastic.
the wrench can repair any damage caused on the plastic, just stroke it gently with the wrench on the tip of the barrel and you repair the engine, or hold it up infront of the rear parts to repair the front part. It's magic, so if would switch this to having the driver sit inside and will his tank back to factory-fresh state instead, would be exactly the same. Only difference being, he could do something in the meantime.
But honestly, I like wrenches. Ever since I bailed out of a panzer on battleaxe 1942 the first time to wand away the smoke and quickly get back in, I have liked this moment. It's exciting and stressing to feel vulnurable outside the tank.