K11 8x15 wheels will they fit?

People have fitted 15x8's no problem, ET20 will poke out a bit I believe, as ET35/40 15x7 is the go-to for flush fitment, so be careful they don't rub on the wings lol. The offset should be ok for clearing the suspension.

I found this really helpful website with a comparison tool, I've pre-loaded it for you with your wheel size and 225/50R15 tyres, check it out if you want. 👌

Hope this helps!