reading nth256's got me wondering when the explorer started. I thought it was in the late 80's but it was actually in 1990 as the 91 model year. So if it was a 91' (in 90) then the concept must have come out in the 80's so off to google images to search for ‘1989 ford explorer concept’. on the first page of results:

and doors that open like this:

o no



but i never found the original explorer concept vehicle