98 and 99 both have the different climate control screen/interface. I think sunroofs were standard in 98 as well. 98 VR-4's are the rarest of all the years.
There was a thread about this at one point. There were a few differences, thought obviously nothing major. Not sure what to search for, but something similiar to your subject may turn up the thread.
A forum community dedicated to all Mitsubishi 3000GT and Dodge Stealth owners and enthusiasts. Come join the discussion about performance, modifications, VR4 turbo upgrades, troubleshooting, maintenance, and more!