He would go on to direct such cult films as Death Race 2000 (1975), Eating Raoul (1982), Lust in the Dust (1985) and Scenes from the Class Struggle in Beverly Hills (1989).

He fulfilled his military service by talking his way into the U.S. Army Signal Corps Pictorial Center in Long Island City and later made films for the United States Information Agency.

After making the 35mm short Italian-language film Progetti (1962) while attending the Centro Sperimentale di Cinematografia in Rome, Bartel produced The Secret Cinema (1966).

Gene Corman's brother, Roger, ran a production company, New World Pictures, and hired Bartel to be second unit director on Big Bad Mama (1974), an action film.

Roger Corman gave Bartel the job of directing Death Race 2000 (1975), a satirical action comedy starring David Carradine, Sylvester Stallone and Mary Woronov.

(1976) for Charles B. Griffith, Hollywood Boulevard (1976) for Joe Dante and Alan Arkush (quite a large role, as a director, which Bartel credited for really kicking off his acting career[2]), Mr Billions (1977) for Jonathan Kaplan (not a New World film but Bartel met Kaplan at the company), Grand Theft Auto (1977) for Ron Howard, Piranha (1978) for Dante, and Rock 'n' Roll High School (1979) for Arkush.

Bartel had small roles in White Dog (1982), directed by Sam Fuller and produced by New World alumni Jon Davison, Trick or Treats (1982), Heart Like a Wheel (1983) for Kaplan, and Get Crazy (1983) for Arkush.

Bartel continued to be in demand as an actor, appearing in Frankenweenie (1984), a short for Tim Burton, Into the Night (1985) for John Landis, European Vacation (1985) for Amy Heckerling, and Sesame Street Presents: Follow That Bird (1985).

He directed two episodes of Amazing Stories, both from his own scripts, both featuring him as an actor: "Secret Cinema" (a remake of his short film of the same name) and "Gershwin's Trunk".

He had roles in Munchies (1987) (produced by Roger Corman), Amazon Women on the Moon (1987) (in a segment directed by Dante), an episode of Crime Story, Baja Oklahoma (1988), and Shakedown (1988).

[5] Bartel appeared in Pucker Up and Bark Like a Dog (1989), Far Out Man (1990), Gremlins 2: The New Batch (1990) (for Dante), Dan Turner, Hollywood Detective (1990), an episode L.A. Law directed by Arkush, Liquid Dreams (1991), and Desire and Hell at Sunset Motel (1991).

Bartel had a large supporting role in The Pope Must Diet (1991), directed by Peter Richardson of The Comic Strip, and was in The Living End (1992) from Gregg Araki, Soulmates (1992), and Posse (1993).

He was in Prey of the Jaguar (1996), The Elevator (1996), Lewis & Clark & George (1997), Boston Common, Skeletons (1997), The Inheritance (1997), Chicago Hope, The Devil's Child (1997), Billy's Hollywood Screen Kiss (1998), More Tales of the City, Race, Vengeance Unlimited, Dreamers, Hard Time: The Premonition, episodes of Ally McBeal and Snoops directed by Arkush, Good vs Evil, Zoo (1999), Hamlet (2000), Dinner and a Movie (2001) and Perfect Fit (2001).

[11] Bartel was openly gay; this influenced his career choice, as he found himself more accepted and afforded more opportunities within the independent film industry than he would have in Hollywood.

His final screen appearance was a posthumous role as "Dad" alongside Mary Woronov ("Mom") in the 2001 independent film Perfect Fit.