Since this thread started, I was trying to remember which vehicle had aftermarket AC in our fleet. It was an Impala about 1980 vintage. It was bought used and had no AC. My dad decided to do one of the aftermarket installs, and it was effective enough, if I recall correctly. I don't remember what all went into doing the install, or how long it would have lasted. I believe the car was totalled off long before the unit's long term reliability could be established. AC was becoming more desirable in taxis in those days, since some customers would specifically request a taxi with AC. After all, why not, when the fare is the same either way?