Our trip around the UK starts with 4 days in London (we also have a couple days there at the end before heading home). After our first days in London, we are heading west to Stonehenge and Avebury, then after that we will be working our way north by car for a couple weeks. We won't have (and of course don't want) a car while we're in London. But once we head for Stonehenge, we will want our wheels.
My plan is to take public transportation (preferably a train) out of London early that morning, heading west in the general direction of Salisbury/Stonehenge/Avebury. I would like to hop off the train somewhere, pick up our rental car at a nearby facility, and then drive onward (to Stonehenge or Avebury). I'm looking for suggestions on where to do that train-to-car switch.
I have not reserved our car yet, but I'm assuming there are nearly endless choices. I'm looking for a location that will work, with major car agencies located adjacent (or at least near) to a rail station.
I note that Heathrow is west of central London, more or less on the way towards our destination, and while I'm sure that's probably the place with the most rental car options in all of England (and it's easily accessible by tube), I don't know if that's an ideal place to begin my exercise in driving on the British side. I was hoping for a less stressful initial experience, in a less trafficy location.
I'd like to take that train west for an hour or two, leaving very early morning, so we can be at the rental agency right after they open in the morning. In London, we'll be staying near Westminster Bridge, in case that matters.
Any suggestions for a target destination where we can best do that train-to-car switch? Thanks!