www.motorsportcollector.com has it for sale, along with a lot of other neat stuff.
I have had a copy on VHS for years and was excited to obtain the DVD version. Then, a few months back on another website I read a post by someone familiar with Paris, who actually went out and measured the distances covered in the film, then calculated the speed traveled based on elapsed times. I don't recall the exact numbers but I was distressed to read that the average speed was something like 48 mph, and the maximum speed was around 80 mph, IIRC. Not condoning street racing, but reading that did burst the bubble somewhat. If the numbers are correct, then I guess it shows how mounting a camera down low can make the pavement seem to fly past.
It's still a great film. I love showing it to first-time viewers and watching their reactions. I have heard that it was a 365 Ferrari, that it was a Matra, that Claude Lelouch (the director) was driving, that a professional driver was behind the wheel, etc. Supposedly Lelouch was arrested the first time he showed the film in public. Don't know what's the truth, but it's entertaining nonetheless.
BTW, along the same vein, check out the "Ghost Rider" DVD, which I think is also for sale at the above site. Superbike riders hitting 200 mph, in traffic--
Edit: you can supposedly download the "Rendezvous" video from this page. I have not tried as it says that the file size is 125mb:
http://www.gremlinnet.com/rendezvous.html