Lowering springs and C30 widening of tracks

Hello together, I’m new here and have a question right away.. At a Volvo dealer near me is a C30 2.0 D MJ 2008 with a really great color combination 😉 Since it is available for 15300€ and has only 35,000 km, I am thinking about whether I should buy it.. I already talked to the dealer and made a test drive for tomorrow.. So now to the question: The only thing I don’t like are the high wheel boxes, it’s 18″ Atreus rims on the car and a R-wheel drive.. Nevertheless, I would like to lower it and widen the track.. Can anyone tell me if I put 30mm shorter springs on the R-dampers, whether the car really goes 30mm lower, or are the R-dampers eh deeper than the “normal”-dampers??? Supposed the C30 would be 30mm deeper, by how much mm per axle I could widen the track with track plates without which I can follow up actions (during, etc.) I would have expressed an absolute greeting now!