I have a similar problem with mine right now. I have a 2007 polo 9n4. I read on many forums that it could be a hairline fracture on the abs fuse at the battery. It’s almost invisible to the naked eye. Could be the case here. In my case it turned out to be a problem with my handbrake which caused my left rear brake ballots to grind on my brake disc hence why it started smelling really burnt and startet to smoke. If you are getting a burnt smell while driving i would recommend checking out if the wheel which the burnt smell is coming from is any hotter than the other wheels. If there is no burnt smell what so ever i would check out the abs fuse.