What year did overdrive exist in manual transmissions?

I've heard that M3's from around the '97/'98 era and all earlier didn't have an overdrive fifth gear with the manual transmission. Can anyone confirm this, and maybe tell me when overdrive did start showing up? Was it not until a six speed became available? The reason I'm asking is because an M3 from around that time is pretty much my ideal next car, but that short gearing is one of my biggest complaints about my current car. Running 3k on the tach at 60 mph is a bummer...

All E36 M3s with a manual were 5-speed, 5th is the "overdrive"

Yes, but I don't think the gear ratio for 5th actually was an overdrive gear. That's what I'm hoping for a little more information on....