Hey,
I'd do it but I'd need to check with some of the local guys here whether summer is the best time to do it. Apparently the heat messes with the cars and they don't run so well. Plus I wouldn't want to be broken down in the desert halfway between DXB and Salalah in the middle of July...
A friend of mine drives his pathfinder to Salalah for kitesurfing, i think he says its like an 8 or 9 hour drive.
How long are you planning to go for? Weekend?
There's another trip I'd like to do - DXB to Jebel Hafeet to Kalba to Sharjah to DXB, but i'm not sure about getting between Jebel Hafeet and Kalba - it looks like there's a couple of roads on the explorer UAE map that could link it up but not sure how good they are.
dry mountain roads + Golf GTI = fun