My $.02 about Ray-Bans...
I've had maybe 8-10 pair over the last 15 years and have never had a problem... The only reason I don't still have them all is breakage (dropping on pavement, sat on, left on car roof, etc.), loss, or theft.
Then again I have never had to send any back... I had a pair repaired for free at my parents' optometrist, though now that I think about it, they WERE sent back to the manufacturer and they were repaired for nothing. I just used the Eye Doc as a go-between, not intentionally of course, they just couldn't fix the problem in the office. The problem was a broken lens, by the way, one of the ones that was dropped.
Question... Aren't Oakleys all plastic? The lenses I mean?