[kach22i]

Can unaerodynamic cars be fast, and be of any use?

You betcha.

http://history.nasa.gov/SP-4220/ch2.htm

Pontiac tow vehicle next to the M2-F1. Walter "Whitey" Whiteside purchased the Pontiac by special order and had it modified in a hot-rod shop near Long Beach for its special mission. (Private photo furnished by Bertha Ryan, NASA digital image ED96 43663-1)

...."Whitey" Whiteside, a retired Air Force maintenance officer who was also a veteran dirt-bike rider and expert hot-rodder.3 Whitey volunteered to help us out by finding, purchasing, modifying, testing, maintaining, and driving the high-powered ground-tow vehicle that we needed.

At the time, the Pontiac Bonneville seemed the best choice, this model so named because it had been the big winner the year before in Utah at the Bonneville Salt Flats time trials. With Boyden "Bud" Bearse's help in the procurement department, Whitey was able to make a special order from the factory for a Pontiac Bonneville ragtop convertible with the largest engine then available, a four-barrel carburetor, and four-speed stick shift. NASA engineers at the Flight Research Center equipped the Pontiac with its tow rig and airspeed measuring equipment.

Whitey took the car for modification to Bill Straup's renowned hot-rod shop near Long Beach, where the straight-piped Pontiac was modified to run a consistent 140 miles per hour. There, auto-shop technicians also applied their hot-rod wizardry to the Pontiac, producing maximum torque at 100 miles per hour as measured on by a [35] dynamometer. They added a special gearbox, with transmission gear ratios significantly different from those that had helped the Bonneville win at the Salt Flats, enabling the Pontiac eventually (once drag slicks were installed) to tow the 1,000-pound M2-F1 to 110 miles per hour in 30 seconds. The Pontiac's souped-up engine got about four miles to the gallon. Whitey got full support from the NASA fabrication shops headed by Ralph Sparks (Sparky). Sparky and his right-hand man, Emmet Hamilton, took responsibility for keeping the Pontiac running and making any modifications required by Whitey.

More of the story in the link.
http://history.nasa.gov/SP-4220/ch2.htm

Sounds like one scary ride, I took my convertible/Targa to 140 once, just once - it was a bit terrifying.