Ok this is an old thread, but my cousin just changed his radiator since his car was over heating at stop lights and what not.
After a normal stop and go drive, his car would spit out radiator fluid from the resivor.

Our Mechanic friend told us to feel our radiator for cool/warm spots as those spots maybe clogged.

Anyways for those who want to change their radiator, get and OEM one. Thats the only way. I got it(97 c280) from Caliber motor Wholesale price $254 + tax which i though was pretty cheap. I am goin to change mine out next month.

Oh yeah his car now runs just above the 80 mark instead of just below the 100 mark. So guess it was a pretty big improvement.

Just wanted to share.