I just lowered my car and have had no problems running a +48 wheel with 225 AO32R's. I don't know if there is a fender difference between our MY's...but just piping in if it helps.
I used to have a +45 wheel and did not rub and sold them to my friend with a '98 GT and they did rub on his. However at the time my car was not lowered. There may be a slight difference in the width of the fenders...but I'm guessing +48 should be fine. What tire size were you planning on running and what suspension do you have?