I put on some Enkei RPF1 16x8 +25 wheels today with 15mm spacers (effective +10mm spacing) and the inside rubs on the stock spring perch standing still. I will try first trimming the lower perch then if that doesn't work, I may have to go with coilovers. This is with 225/50R16 hankook tires.
Update: I trimmed the lower perch, and now the tire clears when down or up, but the spring still is about 2-3mm away from the tire. Since this is definitely not enough clearance, I will be checking camber, then maybe converting to coilovers.