I am coming to London next week for a few days then leaving for Berlin. I want to see Stonehenge, but I cannot find any way to get there under $130 and I despise guided tours. Would it be advisable to rent a car at LHR and drive there? I assume $40 for the rental of a mini-car and (probably way off) $60 to fill it back up upon return and $20 for the CDW (That's what it is in the US, I think)? I've always wanted to drive in the UK, so that is why I am even entertaining the notion of this possibly deadly experience (I did survive the Autobahn, though)!
Also, any of your favorites of London would be appreciated, too. I have never been to the UK before.