Hi Jonathan,
This is Jon from Flash Master Hobby. I originally designed the blades for the trimming of flash on injection molded figures. The slimness and the flexibly have huge advantages and allow you to get at the most hard to reach flash with less force, which translates into more control. BUT, I'm not a model car buff, so I can't give specific examples of how it would help you - but I can say that the blade carves polystyrene so effortlessly that I have to believe that there are many applications in your end of the hobby. In fact, I'm looking for people in different areas of expertise to give them a try so I can get their feedback and answer questions like yours. If you're up for it, I could send you a free pack of 10 for you to check out and see if they are useful to you. If you are interested, please message me on our Facebook page!