hey guys i found out that i have a flat on my 06 525xi...and the car is on the spare wheel right now..does anybody know where i can get the Continential tires that came with the car for a good prices...and also...how long can i drive on the donut without messing up the car?

 

You can try tirerack.com, I have bought from them before and the shipping was pretty fast.
The also have a list of recommended installers in your area and how they are rated.

You should update your profile so people will know which side of the pond your on.
Since you are spelling it tire and not tyre I will assume the US.

As for how long you can drive on the tire I would assume you wouldn't want to drive on
it anymore than 3 or 4 days or 250 miles max, there are alot more knowledgeable people
on this forum that can probably provide some better insight on this issue.