[sambo]

I would probably keep spending on my current car... a 2006 Golf GTI. Yeah yeah, front wheel drive turbo shopping trolley... but I've added a turbo back exhaust, cold air intake and flashed the ECU, giving 188kw and 412nm. Stage III (big turbo, exhaust manifold, fuel mods) would take it to 400HP, but then you need to add the LSD to sort out the torque steer. Add some big brakes and there's your 75k gone.

If I looked second hand I would probably still want something practical... a BMW M3 or 330ci? I can't think of anything else that would make big power, handle well and still be reliable. Porsche maybe?