Yes I've gone and done it, posted another question about wheel fitment! Used the search facility and found loads of good info, also learned a lot about the different measurements that influence look and wheel fitment but not been able to answer my exact question...so here goes...
At the moment I'm lowered ~40mm all round on Eibach Sportline springs.
I have 19" x 8J wheels with ET35 (far as I know) running 235/35/19 on the front and 225/35/19 on the rear. With a fully loaded car (passengers and luggage) there has never been any rubbing or catching issues.
One of my wheels is buckled and I've always wanted 3SDM wheels so been looking at these ones 0.01 Collection / 3SDM Wheels Co and more specifically at the 19" x 8.5J ET42 fitment.
I tried using a worked example but got lost half way through from google. Does anyone know of the top of their head or can work out if this fitment will be the same as my current wheels or will it rub? If I get the 3SDM wheels I'll stick with 225/35/19 all round as it maintains a closer-to-stock circumference compared to 235/35/19.
Ideally I'd love that 3SDM wheel in a 19" x 8J but thats not listed on the site, so can only assume they don't make one.
They offer the stock fitment of 18" x 8.5J ET45 (thats my factory black edition wheel spec from what I've gathered) but now I've seen my car on 19s 18s just look too small