I read the previous posts on this and there was someone trying some customized tip lengths and shapes to help solve the exhaust fume problem. I'd like to know what results he got if he's still around here and can post them. I've go a 73 240 I've had since '76. Its always had an exhaust fume issue with the window(s) down. Since here in Texas we usually always have the AC on its really not much an issue. However, lately the ac is on the fritz and besides it sure would be nice to have a breeze a