Harrock n roll:
the film is (I'm reliably informed) set at a later period in the 1950s. I'm sure another of m'learned Tintinologist colleagues will be able to shed more light on this...
I've not heard that, so I can't shed any light on the film-makers' intentions. However, the film had more of a 1940s look to me. The cars in the street scenes looked a bit more 40s than 50s to my eyes, but I suppose my perception may have been affected by my preconceptions from the books and my assumption that they were following the same date setting. Also, the early 1950s can look a lot like the late 1940s. When we think of the 1940s, we tend to think of iconic stuff from the early-to-mid 40s, ie: stuff associated with the Second World War, whereas things we associate with the 1950s - rock-and-roll music, teddy-boy fashions, iconically 50s cars, etc - tend to come from the mid 50s onwards. So the late 1940s and early 1950s are perhaps a bit less fixed in our minds in terms of iconic styles.
The specific red Willy's Jeep in the Tintin film is, of course, borrowed from the 1948 book,
Land of Black Gold, and is probably based on one of the civillian versions of Willys Jeep produced from 1946 onwards (though I suppose it
could be an early-to-mid 1940s military model that's been customised and painted red).
It's true the books on which the film is mostly based were drawn in the early 1940s, though that means of course that they're set in a version of early 1940s Brussels that didn't actually exist historically, given that the real 1940s Brussels would have been swarming with Nazi soldiers. I was assuming that the film-makers were going for a vague and unspecified 1940s look, aimed at capturing what they see as the nostalgic appeal of the Tintin books without pinning it down too much. (Not that Hergé himself was into nostalgic settings, of course. Being something of a modernist, his books tend to be very much contemporary with the time in which they were drawn.)
To be honest, if the Tintin-book fan in me was going to be annoyed by anything whilst watching that scene, the fact that the Jeep's being driven by a character who's a dumbed-down villianised version of one of Hergé's more interesting minor characters, and who's been motivated by a ludicrous ancestor-avengement complex to steal a parchment using the unbelievable contrivance of an opera-singer's voice, would come much higher on my list of objections (along with many of the other objections many of us have listed) than the fact that the Jeep is possibly four or five years too late for the original setting of the books! ;)
Given that I'd mostly managed to suspend these objections in order to enjoy the film as a non-Hergéan Speilberg movie (helped, as I said in an earlier post, by the fact that my 10-year-old son and his friend were enjoying it), I actually enjoyed seeing the red Jeep shoe-horned into the film and thought it made quite a cool baddie getaway vehicle.