I ran this through willtheyfit.com
Got this summary;
Compared to your existing wheel, this new wheel will have an inner rim which is 8.4mm closer to the suspension strut. The outer rim will poke out 42.4mm more than before.
Thats more than 4cm of extra track and 8.4mm closer to the strut on the inside. You will also over read on your speedo by more than 2% as overall youre losing a fair bit of circumference. Depending on how low you go, you will probably need wheel arch surgery.
Ive looked into rims a fair bit myself and it looks like et49 is as far as you can go widening the track without bodywork issues.