Swiss Vignette - would it work here?

[johnnywb]

If you drive on the Swiss Motorways you have to buy a sticker for your windscreen. Not hugely expensive, about £25 or so from memory.

Now here's a thought, why don't we have a similar thing in the UK, only do it for all roads. We all pay road tax already, so why not collect £25 off every jonny foreigner who gets off the ferry? Valid for 12 months, could be a nice little earner?