Justimagine, ya gotta get your details right if your gonna post like this in the future
fist of all,the Batmobiles for the films both of em were made of fiberglass inc;luding the "hero's" and were not built on stretched firebird chassis ,perhaps the second one was but the first ones were two stretched imapalas, and fiberglass for the touring cars as well,even came out of the WB molds.so therey were basically accurate as the screen used ones.
second,if you saw a Batmobile that was polished to a high shine,then you saw batmobile 2 not 1... the first one wasn't even Black it was a dark satin gray silvery finish at least in special lighting..i broad daylight it was simply Dupont laquer non-sandable primer gray,a blueish greenish tinge to this color. Ironically,this color was also used on another dark looking movie miniature...the "hero" miniature,Firefox
If you read your own post...you will notice that you are litrerally describing "Batman returns" Bat car 2 which also wasn't black but a very dark green witha hint of black added then a pearlescent clear applied to give it the gaseous look, then polished to a very high lusture..Bat car 2 also had windshield wipers and a different interior...I have high res photos of both cars,used em for ref to do the detail drawings used for the new 1/18th scale Kreaton 1 film Batmobile just released by Mattel,Hotwheels division.
it was helcopter parts actually used(toggle switches and buttons ,as well as sound panels. Again, i have extreme close ups of these too,so i'm curious as to what jet parts you refer to...this is of course for the first car....the second car was fitted with standard VDO guages for the most part. ya got the hot air balloon burner thing pretty close as,basically that what it was..hope this helps set things straight a bit...if ya got any more questions as to the origin of my knowledge of these cars,feel free to email me questions...
Best
William