Nankangs are piss poor!! My ex stuck a pair of NS2's (after I told her to get Conti's but she decided to save a few quid) on my old 1600cc Audi estate and they couldn't even reign that in. First time she went round a damp roundabout she almost wrote the car off. I ended up skipping a pair of nearly new tyres fitting the Continentals I told her to fit in the first place. Oh and of course the whole thing ended up being my fault!?!?
I would be looking at either Kumho or maybe Falken. I would also be looking to change them for the correct profile while your there.