There are a lot of dead badgers round here on the roads, that's true. But maybe it's just the time of year. I fear this rumour might come into the 'people capturing foxes and taking them into the cities' category (or was it 'people capturing urban foxes and taking them into the country'?!). Most people wouldn't see a badger if it was killed on private land somewhere so why stick a stinky dead badger in your 4x4 so you can shove it out on a road. But if it gives bad press to badger haters then I'm all for spreading the rumour far and wide haha.

blimey there's even a graph here.
http://www.badgers.org.uk/badgerpages/eurasian-badger-23.html