Driving back home to St. Louis from the Hot Springs AR area, it was about 9:45 PM and we were in Cape Girardeau MO. I'd been driving for 5 3/4 hours, and still had another 1 3/4 to get home, so I was mainly concentrating on the road. When about a mile from the Southeast Medical Plaza, which I could see, I noticed what at first appeared to be a large sized commercial airliner approaching a runway, taking its near landing approach across I-55 and over the Plaza. I couldn't help but notice this as it was taking place directly in my line of vision. I live in St. Louis about six miles from its international airport and am quite familiar with approaching aircraft to an airport. These lights were at a declining angle towards the ground, passing over the Plaza at about 500', the length of lights about 300' in length. Having better than common familiarity with conventional aircraft lighting, I couldn't quite discern what I was seeing, also wondering why in the large expanse of land available would a runway by built just a few hundred yards east of the Plaza? I didn't think Cape Girardeau had a commercial airport, so I asked my passenger and she said she didn't think so either, and then mentioned that she'd seen some other strange lights just before acknowledging the lights passing in front of us when I asked her if she knew what they were (no). As we passed the Plaza, I quickly glanced a few times expecting to see the the craft coming down to a runway, but as I last saw it it instead seemed to have banked right slightly and had leveled off! I was confused, I'd just seen at least six distinct lights that appeared to be fixed to a single indiscernible "airplane" decline down to the ground right in front of me but level off and bank right, a craft least had to be 300' long from first light to last light. The front light was white, steady but strobbing. Then there was a distance and there were two white lights close together - these three white lights seeming to be "in-line" on the craft. The last three lights were in a tight triangle a distance from the two "middle" lights, but appearing to be slightly higher "in-line" on the craft. If the object were a plane, the front light appeared to be under the nose, the two lights under the center where the wings would be, and the last three as a small triangle in the middle of the tail of the "airplane". The top lights was green and the two bottom lights were red. This did not appear to be an FAA regulation lighting arrangement for a helicopter nor airplane based on the direction of travel of the craft. When I noticed the strange green and reds triangle, I remember having read that when seeing strange lights that one should try to discern a pattern to the lights. I would say the pattern I've described I saw more than once when looking and glancing at the lights, but the rear triangle of green and reds sometimes appeared to be white instead, where sometimes they were green and reds, and sometimes they were white. Anyways, I and a passenger witness thought these lights were strange, seeming to be on approach to an airport that wasn't quite there.Since that sighting, I did some research using Internet maps and found that I had just passed the Cape Girardeau Regional airport about a mile before I started seeing the lights passing over I-55 and the Southeast Medical Plaza! It was because of the street view of the maps that I figured out it was passing over the Southeast Medical Plaza, at the time I only knew I was in Cape Girardeau and hadn't realized I'd just passed the Regional Airport!! Note again, JUST PASSED the regional airport, it was BEHIND me at the time I saw the lights. So, ironically, I'd just passed an airport without realizing it and was passing a sign with the mileage to St. Louis (where I was going) without realizing it when I was actually seeing the craft!!! Anyways, hopefully there is an image associated with this report depicting what I and my passenger witnessed in Cape Girardeau as we were approaching and passing the Southeast Medical Plaza at about 9:43 PM as Memorial Day evening.