I have a slight rumbling/vibration most noticeable when driving at low speeds. It is felt through the footboard and sounds like it's coming from the front of the car. The sound slows as the car slows, so it is most likely a driveline problem. At freeway speeds, I can't hear it, but there is a definite vibration.

Does anyone have any suggestions as to what it could be?

I know this may sound stupid, but Is your emergency brake up?

I have a '86 5000 turbo. I think the vibration is due to misallignment in either the brakes or the wheels. I'm getting my car fixed asap - a misallignment means that either the brakes or the tires are wearing unevenly - I saw the effects of misalligned wheels - I had my tires changed about 4 months ago - the inner side of the right tire was prety bald while the other side was not half as worn - so have a mechanic check it out and get it fixed ASAP!

My 2 cents.