Musclecars in Movies...And the screw-ups!

We all enjoy seeing musclecars on film, but sometimes I wonder what the producers, directors and stunt coordinators are thinking. In the new revenge flick "Faster" starring Dwayne "The Rock" Johnson, he drives an SS396 Chevelle. It's apparently supposed to be a '70 model, as that's the front end it has. However it has the round taillights and rear bumper of a 71-72 model!! This is a big-budget film. I figure the stunt crew took a beater 71-72 Malibu and tried to trick it up. What irks me is-Just make it a 71-72 SS454 clone. Or if your going to to put the '70 nose on it, they couldn't afford another 300 bucks for the correct '70 rear bumper? "Fast and Furious 4" starring Vin Diesel and Paul Walker went with mostly musclecars this time out instead of imports. Sorry Mopar fans, only the "Show" Charger-i.e. the one at movie premieres and photo ops had the blown 528 Hemi. All the other stunt Chargers used in the movie had-Gasp!- GMPP 350 Chevy crate motors, Turbo 400 automatics, and 9 inch Ford rearends. The blowers were fakes that were bolted to the hood. The stunt crew said they did this for reliability and parts interchangeability reasons. I've been playing with cars for 30 years, and I don't know anyone who's ever broken a Chrysler 8 3/4 or Dana 60 rearend! Reliability reasons? The 350 Chevy/Turbo 400 combo is that much tougher than MP 360 Crate motors and 727 Torqueflites?  At least the 70 Chevelle that Diesel did the wheelie in had a 502 rat motor, Turbo 400 and a 4.88 posi. It also had 300 pounds of lead in the bumper to make it pull the wheels easier. This is not a new phenemonon-Hollywood has been screwing up for many years. In "Smokey and the Bandit" sometimes the Trans-Am is a four-speed; the camera shows the clutch pedal and Burt Reynolds shifting it. Other times, the camera clearly shows the automatic shifter sticking out of the console. In Burt's other classic "White Lightning" regarding the 72 LTD he does his "Whiskey Runnin'" in-when the ATF mechanic shows him the chromed out engine Burt says-"Nice 429, dual quad carburators.." Yet the camera clearly shows one Holley four-barrel under a Weiand Lynx air cleaner. Later, again, in some scenes it's a four-speed-they show the T-handled Hurst shifter, and him shifting it. In two other scenes one where he visits his mother-he clearly puts the automatic column shifter in park. In the other, Jennifer Billingsly drives the wounded Burt to safety. She starts the car, and pulls a column shifter into drive before taking off.  In "Vanishing Point" if you look closely, the car that explodes at the end is a Camaro, not a Challenger. Stunt coordinator Carey Loftin freely admitted this in a later interview. "We took a beater 1967 Camaro, pulled the engine, and filled the engine compartment with explosives and an impact-sensitive switch." "I used a quick-release tow bar and towed it toward the bulldozers,released the cable and pulled over." "That's how we made it look like Barry Newman actually drove into the bulldozers." My question is this- The movie was made in 1970 and released in 1971. The cars were brand-new. Chrysler supplied them with five Challengers-four 440/4-speeds and one 383/automatic. They couldn't blow up one of those? They couldn't ask Chrysler for one more, even a strippy slant-six model to blow up?  In 1970, a 67 Camaro was still a pretty new car: that would be like blowing up a 2007 model of anything now. I doubt they got the car for nothing. So why use a Camaro instead of a Challenger, and hope no one notices? On a movie that had a budget of a few million 1970 dollars, what did they save? 3 grand?  In the all-time king- Bullitt-the Charger loses eight hubcaps in the chase, they pass the same VW several times, and the gas station explodes BEFORE the Charger hits the pumps. I know nobody's perfect, but this wasn't the "Jackass" crew with a video camera, these were major Hollywood releases. Like Ditka says on Monday Night Football- "Come on, Man!!"  Mastermind