With over 500 views and no right answers, here are the answers which I suspect will be a huge surprise.
1. Beech Aircraft Company of Wichita, Kansas.
2. 1946.
3. Beechcraft "Plainsman" four-door four-wheeled power fastback six-passenger sedan.
4a. A four cylinder air-cooled Franklin aircraft engine was the motive power. 4b. This engine powered an electrical generator which sent electric power to each of four electric motors that propelled the four-wheel drive vehicle. One electric motor per wheel.
5. Top speed of the streamlined car was 160 mph.
The sleek body was all-aluminum weighing 2,200 lbs. The streamlined car had a low combined grille and front bumper. The sloped windshield was large and tall in relation to the four-door body. The four "Bonanza-type" doors and their windows as well as the windshield curved into the car's roof line just as the original Beechcraft Model 35 Bonanza built in 1946 and 1947 after first flying in 1945.
The "Plainsman" was a full six passenger smooth and handsome distinctive-design automobile with generous window area that curved into the roof and streamlined to achieve a top speed of 160 mph. The rear tires were partially covered by the body low to the road surface. The trunk was streamlined into the fastback without any protruding handle. The one-piece hood curved down to the low grill/bumper without any chrome on the hood. Dual headlights were recessed flush with the rounded body work. There were no side view protruding mirrors. The tires had typical "fat" whitewalls of the period. The car had "automatic" air suspension. Visual emphasis was on smoothness, and tight panel fits resulting in the high top speed and 25 mpg economy. The anticipated sales price in 1946 was about $5,000.
Now, I stated in the quiz "who built automobiles" in the plural. Beech Aircraft Company built just two of the "Plainsman" automobiles. I have several photos of the automobile but do not reproduce copyrighted photos of others.
I thank all who pondered this somewhat different aviation quiz.