In Todd McCarthy's Howard Hawks: The Grey Fox of Hollywood, the impetus behind RL7000 was a) Hawk's 10-year old son Gregg was into cars, or b) Hawks wanted to prove he could make a commercial film quickly for a million dollars. Too, Hawks loved cars, studied Mechanical Engineering at Cornell, raced cars after college, and made the racing film The Crowd Roars (1932) giving him the opportunity to work with Cagney (and wrangle a Deusenberg for himself from the Deusenberg company in exchange for product placement). In a sense, both films are indulgences which never translate into a coherent picture.
RL7000 comes off a bit more like a Roger Corman film than a Hawks film, probably due to budgetary constraints. We see lots of young unknowns, dancing, loud music, interludes of unevenly-acted drama interspersed with bouts of frenetic action. Caan is a good, brooding Bradoesque study, though he squints and smirks to distraction, Marianna Hill looks great, and seeing cars like Cobra Daytonas is pretty enjoyable for mid-60's sports car fans. Ultimately, the film has problems because Hawks doesn't get what he wants out of the actors. All of his other films have very strong acting; Hawks could always get great performances from Wayne, Grant, Bogart as well as the veteran character actors he used. He didn't have such luck with most of the primary cast of three men and three women. Their bonding as lovers and as male and female groups is integral to the credibility of the film, and it just doesn't happen.
Another possibility explaining the film's weakness is that this is the only one of Hawk's final six pictures (Rio Bravo to Rio Lobo) without writer Leigh Brackett on the team.
One also senses that Hawks tried too hard to be "hip," perhaps in reaction to the fact that some critics had complained that his previous picture "Man's Favorite Sport?" seemed old-fashioned. Thus the plot is periodically suspended for some truly bizarre song and dance numbers, even by mid-60's standards. It seems inconceivable that "Wildcat Jones" was given us by the same Hawks who gave us the immortal "Diamonds are a Girl's Best Friend" number.
I want to like this movie, since I do subscribe to the school that a great director can never make a truly bad film. I also happen to love "Man's Favorite Sport?" which often critically lumped in with RL7000 as the two off-the-track films between a pair of Wayne/Hawks collaborations before and after. Furthermore, there are some vocal critics who love the film, such as Robin Wood. So I guess I need to watch it a few more times and hopefully can write a better review next go around.