fukken problems with new 92 cav

hey all, i got my cavy on the road, finally, pics to come, but now when i drive i get this burning rubber smell and its only when ive been driving for a while, there is smoke coming from the cat that smells like burning rubber...confused there, 2nd thing, Neons, there flashing when i turn them on, they have good connections all round, and its well grounded, but when i fuck around with the transformer it works just peechy any clue what im doin wrong? Third, when im crusing between 80-90km/h (50 - 60 mph) the cart has a very noticable vibration through the whole car, i have a flowmaster 40 Dynaflow series on the car, could it be hitting a resanant frequency thats causing the car to shake?

thanks guys i need help with these