Hey there,
Im new to the board as I am also new to the Grand Prix. I traded in my 99 Cougar for an 04 GTP. When I had the Cougar I always went to the same guy for my exhaust welds. He doesn't have a mandrel to bend the pipe, but he can simply flare out the pipe at the kinks, which ultimately gives the pipe the same diameter all the way down.
The only reason a mandrel is desirable is to maintain consistency of ID throughout the pipe. If you flare out the pipe wider than the rest at the kinks, then the ID stays consistent anyway.
Anyway, my guy is Steve at the Car X on North Ave. in St. Charles. When I get my Borla system he'll be throwing it together for me.
Hope this helps.
-John
'04 Silvermist GTP - Nothing... yet. Loving the power, hating the shifts -sigh-