I wish I had a £pound for every hour I've experimented/wasted with bitmap to vector software trying to get a usable result with a good workflow.

Then I discovered the Brands of the World free vector library.

If it's a popular & well known brand logo then it'll be on there, I'm really only interested in motorcycle related logo's & I've usually found what I'm looking for. If it works for bikes, then it should be vgood for everything else.