didnt seam to fly on air / had speed of light

Me and two friends, everyday when we got off the school bus ,would sneak and get into one of are parents car or truck and drive to a store that was close by to buy tobacco or cokes just fooling around,and that day I was on the passenger side just looking kinda at the sky as fare as I could see at the tree lines, and a black mantaray shaped craft came over the tree line and it just seamed to go, not fly and it done this about 40 feet off the ground kinda looked like it contoured want ever it went over as it came toward us it seamed to slow down,and it was about 20 feet when  we drove right under it and got a look at it from all sides,the craft made a humming sound and you could smell something like weeds burning,it had round port holes and the front looked like something you see on the stealth fighters,the underside was flat and seamed to have four grate looking squares,we never lost site of it for awhile and then all at ones it whent from maybe 500 feet off the ground to about 6,000 feet in about 2 seconds it seamed to hover there for about 3 seconds and then it whent at a 70 degree angle across the sky in a blink of a eye,that was 20 years ago and people we told thought we all were crazy,but to this day I have not seen anything like it.It did not fly it whent how ever it seamed to want to go kinda like it was in water just like a mantaray and it even looked like one. if their is anyone out there that has seen what we saw that day, you are not alone three boys from a small town, saw one too.
Date is approximate.  PD