2000 SES Flex Fuel Vibration

I test drove this vehicle today. It has 99,000 miles, is very clean and appears to have been well maintained. The only issue is a slight vibration. Car has four brand new Pirelli Tires and was recently aligned. Seller is willing to replace front rotors, however, vibration isn't noticable when brakes are applied, so I'm not convinced that is the issue. Front end shop has checked it out and can't seem to find any problem. Struts and shocks seem fine. I ran a Carfax, and it shows four wheel ABS. However, the car has drum brakes in the rear. I thought ABS was only available with four wheel discs.

Any thoughts?

My last two half tons had ABS and drums in the back. I don't think ABS is specific to disc brakes.

Wheel balance.

I have 2001 taurus SES Flex Fuel with abs and rear drums. After 1999, ford went back to drums as a cost saving measure. Good job ford! As for the vibration, I would also say wheel balance. Worst case, could be a slightly bent rim.

Thanks, all! The seller installed new front rotors and pads. She also put four new Goodyear tires on instead of the Pirellis. I don't think the Taurus is meant to ride on Pirellis as the vibration is gone!