Just replaced all four corners on the GTV with new rubber.
Nothing exotic (Kumho Ecsta 4X II - 205/55/R15s are an unusual size so choices are fairly limited) but OMG what a difference.
The clapped out Goodyear Eagles were just about shot (and no longer available in that spec), but I guess I just got used to it.
Unbelievable how much nicer she now rides, grips and steers.
Probably the best 'mod' you can do to any car, a good set of tyres with a good alignment. Love my new Bridgestones and I too couldn't believe the difference it made in both the grip and comfort.