The best solution to help with understeer is getting wider front tires. Everyone has already said this, but I thought I'd tell you from experience. I was on FR 245/35R18, RR 275/35R18, then went 275/35R18 square -- night and day difference.
Also, I just got RE71s and highly recommend. I hear the RS3s are decent as well. On the stock 19" wheel, it looks like you can go 275 or 285 square on RE71s.
RE71s
Shocks (konis) will help the cars handling and your times might decrease, but if you're in the middle of a large sweeper with the narrow tires, you're still going to have the understeer. This was true in my experience when I had Konis and narrow front tires.
The 370 can be competitive in B Street (where I plan to stay). Not sure how well it does in ASP or other classes.