To tell the truth, I liked this movie. It's not great, it's not even good, but it's a very entertaining piece of budget movie history, and considering that I am surprised at how good it actually became.
Basically it is a classical Dirty Dozen/Guns of Navarone mixture. Group of misfits in German penal battalion goes on impossible mission, shot lots of ruskies, loose some good men and have some strange/amusing/other encounters. The acting isn't bad, in fact it's downright good in a few spots such as Tiny and The Legionaire but generally it's pretty mediocre. What makes this movie something more than B trash is the fact that it has some pretty likable characters and some pretty funny scenes.
For example; throughout the movie we are given propaganda bulletins on the German radio talking about the heroes of Bektovka, who are holding out against all odds far behind enemy lines. One is compelled to laugh at the absurdity when our heroes accidentally end up at Bektovka and discovered that the 'heroes' are living a quiet farm life together with the Russian defenders of the village.
Another fun thing, at least for me, was how equipment and uniforms change continuously throughout the movie. At one point even the German tanks (which look suspiciously like Russian JS3s) are transformed, into Russian T-55s.
Wheels of Terror gave me a feeling of watching an episode of the 60s WW2 series 'Combat' or the old Polish series 'Four Tankers and a Dog'. If you're looking for a good war movie see Peckinpah's 'The Iron Cross' or Stone's 'Platoon', but if you're looking for a trip down nostalgia lane Wheels of Terror is the movie for you.