In case anyone has use for it, I now have a subscription for
VectorMagic.
The results vary from logo to logo - it has lots of trouble with greyscale shading (on, for example, the Renault and Honda badges) - but it works fairly well in most cases. Not as good as a hand-drawn vector by someone who knows what they're doing of course, but it certainly passes for most uses.
But you need a subscription to be able to download the vectorised file.
If you have a logo you need converted to a vector, try that site.
If you like the result, send me a PM with the file you'd like converted and I'll do it for you.
F1 Graphics Swapper ---
Lensdump - Renders and Screenshots ---
GP4 Performance Generator