So my car is currently on coilovers, as it was when I bought it, but I have no idea what height it is set at. I am pretty certain the driver side coilover is knackered (there is next to no bounce back if a bounce on it, there is on the others). When I am driving I have some issues. On the likes of B roads, I get quite a bit of scraping on the tires, no constant, but over every tiny bounce. On regular roads I get scraping on hard lefts. The scraping is only on drive side. I wouldn't care, but it is causing damage to the tire. So that is the back story, now for my thinking.
THE WHEELS: I have 15" Borbets with a 7" width. I can't make out the offsets on them, but I calculated it to be ET25. This calculator (
http://www.1010tires.com/Tools/Wheel-Offset-Calculator) shows that means I have 16mm less outside clearance than a standard set of BBS. Probably won't help.
THE SUSPENSION: As mentioned I think it is partially f**ked. But also too low, I know it isn't as low as some of you guys have set up, but it is a daily car, and tires are expensive... So, I plan on fitting springs and shocks. With a 30mm drop. Question is, will this actually give me any more clearance? Would love you guys thoughts on what ride heights combine drivability without looking too high.
I know this is a wall of text, but I really appreciate the help before I shell out on new suspension.
These are some pics of the car, and wheel in question:

