Hi guys! I have neither Toynami's version nor HT one (which I believe is still not available). However I also believe that Toynami's one is more correct both in terms of proportions and movie likeness. It just LOOKS more right than HT. And I am talking now only about the actual SHAPE of the car disregarding the painting and additional features such as machine guns, etc. provided by HT.
Also, you can try to compare them to the real-life car actually used in the movie by looking at the attached photos I took at the Warner Brothers museum in Hollywood.That's the best shots I could take given that the car is fenced off and you can't actually get to it or behind it.