Yo. I'm also getting some new rims very shortly. I am also going 215/35R18. Number 1-Yes they do fit. 18x7.5 no problem. I'm pretty sure you can go 18x8 with the right offset to fit, otherwise, you most likely will experience inside tire rub when turning. Your speedo should read slightly faster at 100km/h then it did stock. I think its 0.624% too fast (that's from going 60mph stock to 60.3mph with 215/35R1
. I'm also pretty sure that the ride height is barely noticable. Actually, you'll be sitting 0.17 inches less than you did on stock.
Hope that helps...
What kind of rims/tires you looking at? I'm pretty sure i'm gonna go with Konig Theory Graphite with machined lip 18x7.5 (20.26lbs) with Falken GRB FK-451 tires. I'm pretty gonna purchase them in the states cause currency exchange is kick ass right now. I can get the whole deal rims/tires that I mentioned for $1555 Canadian.
On an interesting note... it will most likely be hard to find Konig wheels right now. The company couldn't keep up with the demand this spring and the warehouse is basically empty ROFL