I have just fitted a set of GSD3 to the front of an astra, VERY unimpressed, hope they get better as they are not a patch on the Uniroyal Rainsport 1 they replaced.
I had GSD3 on a mondy years back and all developed sidewall bulges which is VERY COMMON with these tyres, never had it on any other tyre in 25 years!!
tabetha