listen mate, leon offset is et38 i checked my lcr alloys when i was washing them last week, also are the spacers h & r. i got spacers on the front and rear also, just last week in fact, and i had much the same problems as yourself, steering wheel vibrating from side to side, car vibrating, i phoned skidz who i got the wheels from they told me to bring the car straight back, after much head scratching they found that the front spacers had a machined lip on the side that fits into the wheel, therefore the spacers were not sitting flush inside the wheel, ( spacers are hubcentric by the way ) the fronts are 10mm but the backs are 15mm for some reason the backs were fine (h & r as well). get the place that fitted the wheels to check the spacers for this mate, although i think that the wheels are definately the wrong offset for your car and i don't think any wheel should touch the callipers on a leon cupra, the reason i've got spacers on mine is because of the BREMBO's. et45 sounds like subaru wheels or something like that. get it all checked out though mate.