I have a '93 fleetwood brougham and it seems the steering wheel shakes a bit while braking or even when the car is rolling along at 5 MPH. Now I had a nail in my right front tire and it was a bit low on air when I took it off and put the spare on. It still does it with the spare on there to but truth be told neither tire is really that good and are bing replaced soon. Could this be a tire issue or a warped rotor? FWIW I replaced the front brake system in may of this year,this included the pads,calipers and rotors. What are the chances of me having a bad rotor(s) in a new set?