I don't think car Wars qualifies as a RPG any more than, say, Battletech does.
Given that CW, since the Compendium-deluxe edition's premier, includes a bunch of non-combat skills, and that the Truck Stop subtitle includes Role Play, and that many of the ADQ scenarios are very much RPG mode. SJ said it was an RPG. Aaron Alston, who wrote a bunch of adventure modules for it, also notes it's an RPG. Even contrasting it against Highway 2000 and Battlecars.
Battletech only has vehicle operation skills included. Piloting, Gunnery. Piloting is specific to a category... but to get non-combat skills you have to go to Mechwarrior.
Car Wars, from Compendium 1 on, includes Area Knowledge, Animal Husbandry, Computer Tech, Engineering [Vehicular Engineering], Espionage, Fast Talk, Hobby (specify), Journalism, Law, and half a dozen vehicle skills in what has been, since 1987 or so, the core rules of the game. The ones I noted above? When is Animal Husbandry going to come up in non-RP play of the game? Or Espionage? Or, given the 1 second rounds, Fast Talk? Clearly, the intent is that there's more than just combat.
the GURPS version of the setting, GURPS Autoduel, was NOT being asked for by most of the CW fans... it was being asked for by GURPS fans who didn't like Car Wars' rules... and yet, in keeping with the GURPS 1E philosophy, GAD converted GURPS to the Autoduel Setting, used a close variant of the Car Wars Rules, and pissed off most everyone - it was too much CW for the GURPS side, too much GURPS for the CW side, and too much of both for a lot more. Hence, after GURPS Vehicles was written, GAD2 was a pure GURPS thing... and none of my GURPS fan friends would touch either one. The CW fans felt no need to go to GURPS.
I've only played about 4 duels-as-duels. I've played two highway chase scenarios that weren't part of a campaign. I've run 3 or 4 amateur night scenarios which weren't RP. I've played one drag race (yawn). Everything else has been within an ongoing campaign structure with continuing characters and upkeep expenses, maintenance, and repairs.
If
D&D OE counts as an RPG, Car Wars does, too. Car Wars has more about downtime than D&D OE. More character types (largely by being skill driven). Actual costs of downtime. Mention of day jobs (and for mechanics, how much pay.) And it's not like SJ didn't write hybrids before... (original TFT core rules are the two boardgames,
Melee and
Wizard, and the book
In the Labyrinth.) Later, SJ would prerelease GURPS' core mechanics as a boardgame, too - Man to Man.
I'd never argue BT is an RPG, largely because FASA never intended it to be a hybrid; the hybridization was always put in the RPG module.