[Biturbos4] Accelerating "thud"

[Aurangzeb M. Agha]

Here's the answer: Don't know how we missed it (both my mechanic and I), 
but there's a bulge in the tire, probably from hitting a pot-hole.  It's 
not completely obvious and have to look for it, but it's there.

For now, I've moved that tire to the back to reduce the feeling.  Now I'm 
stuck with this problem: the 2nd time in three years:

I have three good tires and one bad one--and I can't find a replacement 
for the bad tire: Dunlop SP Winter Sport M3 DSST 91H (225/45/17)!

What do you guys do?  Put $800/$900 worth of tires on your car, have one 
go, and start over?  Put on some other brand that doesn't go "out of 
stock" or "discontinued"?  Please advise--new tire buying is becoming a 
very expensive hobby!

 	Aurangzeb

--
'01 Silver S4 (stock)