Daylight. Large rectangular (not cigar) stationary in sky

I am only reporting this as over the years I have never heard.mention of any other rectangular shapes being reported and have puzzled ever since as to what I saw and why no one else has mentioned rectangular.  It was angular and definitely not the cigar shape that was the only other similar shape known to me back then apart from the disc which seemed to be the only other reported therefore I didn't know to whom to report it other than family and friends over the years.
I was in the front passenger seat of car...my husband was driving.  It was early morning summer day clear skies...not a cloud or haze in sight.  We were on a section of dual carriageway...other road users also...in a rural area but commuting stretch of road.  I either sensed or saw something just outside my vision to my left and turned and looked out the window straight out and up to a very large dark metal looking object...massive and stationary in the sky.  I looked at it clearly ... thoughts through my mind that it was clearly something big, unusual and not moving surrounded by blue sky and not joined to the ground in any way...this sounds strange but I was almost looking for it to be joined to something on the ground as a way of explaining how it could be.
I told my husband quite desperately to look but it was not visible to him driving and was til high for him to see from his seat...I kept eye contact with it for a good minute and it remained stationary and I had to turn my head to continue to see it.  We passed behind light trees and I could still see it's broken shape and mass.  My husband took the first road on the left which brought us behind the line of trees and when I looked behind them it had completely disappeared.
It was the size of a passenger plane...I drew it after the event and I would guess it was only 100 to 180 feet above the ground...a green slightly sloped field.  It had darker markings on both ends but was definitely angular and rectangle...possible 10 times as long as the height.
At the time my husband and I discussed how I had no reference to gauge the size snit was just stuck in the blue sky with no other structures around it but I could gauge how close it was and it's size as I could see markings and the edges were crisp and it was solid and close enough for me to know it was nothing that I would ever expect to see....it was nothing that I could explain with any physics known to man unless it weighed absolutely nothing and somehow didn't move in a breeze!  I really just wondered if you had any either reports of this size and shape and particularly as I saw it in daylight and stationary.
I do think I am trustworthy witness...not taken to flights of fancy.  I was in the army previously and now work as a paramedic just more interested to know if anyone has reported the same.