Ptrs clown car and shreks are used to bully light vehicles quite often. It's especially good to run down flamer HT or univeral carrier for easy kill.
Hans has pulled it off once or twice, Jove I've seen use both. And captain molo uses clown cars like a fine wine, you imagine the unit inside and he's done it.
That's why I think 30% moving accuracy is a bad idea to implement for all open halftracks. You already can't target with the squad inside the halftrack, so you have to go through great lengths for the squad not to waste their shrecks/zooks on infantry. A further 40% accuracy nerf would simply make the risk not worth the effort, a 250 with shrecked pgrens is worth 550 manpower, 100 munitions and 20 fuel, for example.
I suggested earlier that the amount of models firing out of the USF M3 should be reduced from 5 to 4. This way the performance of cavs is reduced, while the tootsy strat remains untouched. If that's not possible, make the moving accuracy penalty 40% instead, so you end up with the same total dps as other halftracks (5*0,4 vs 4*0,5).