Hi and welcome mate. Just reading through your thread and thought i would re-iterate, DON'T go back to standard suspension set up, SERIOUSLY! As the others said, could raise it slightly as a compromise, but with stock suspension, you may as well be driving the QE2! Air filter, I would go with the BMC as it has built-in heat shield. You get an awsome roar when planting your foot, but sounds normal otherwise. As for your wheels, i like 'em mate. But the standard BBS are also nice when in good nick. Really sort the car well.