These are quite cool cars, my sister loves hers!
You can't get that bigger wheels on them, we've got 18x9.5 et35 with 5mm spacers on the front, with 235.40.18 tyres, any wider and the tyre would hit a metal box at the front of the o/s wheel arch, I'm not 100% sure what it is, so it may be able to be removed/relocated.
You got the thread title wrong too, it's not a Chaser!
Alex B