After 5 days in London, I'd like to venture west of the city towards the Cotswolds. I'm not familiar with the roads and traffic, so I don't know if the following plan involves too much time in the car.

Leave London on Friday, stay in Upper Slaughter for two nights.
Sunday: Drive to Amberly Castle
Tuesday: Noon flight out of Heathrow.

Is there anything of particular interest to see on the trip from Upper Slaughter to Arundel, West Sussex? I would define too much time in the car as near two hours, unless there is an intermediate stop of interest along the way.

You need to get a map--the Cotswolds are north and west of London and Aurndel, West Sussex is south of London. Still, the two locations (Arundel and Upper Slaughter) are probably around two to two and a half hours apart, but traffic can be a huge factor and add easily an hour on to that. I would spend the enire time in the Cotswolds and perhaps visit Blenheim Palace or Warwick Castle in the immediate area.

Amberley Castle - if that is what you mean, is nowhere near the Cotswolds. It is in West Sussex not far from Brighton.

Certainly doable but it is a looooong drive from Upper Slaughter and a longish drive from Amberley to LHR. So you won't have more than one day free in the south. W/ a noon flight you want to be at LHR by about 9 AM. Earlier actually since you have to deal w/ the car return which is off the airport.

Before deciding on these two locations, I'd consider 1) staying the full 4 days in Kent and Sussex and forget about the Cotswolds this trip -- or 2) stay in Upper Slaughter and look for someplace else to stay Sunday/Mon nights to the west of LHR -- In Wiltshire, or Berkshire, or near Bath.

Either option would be a LOT less hassle/driving

Didn't see cathinjoetown's comment - I'd probably put the drive closer to 4 hours for the typical visitor.

As for what to see in the two areas - there is MUCH more to see/do in EITHER area to completely fill your 4+ days. And don't underestimate the time/hassle of getting to LHR on a weekday morning.

Excellent feedback, thanks! My wife and I would be happy to roam the Cotswolds for four days. My four year old daughter only wants to "stay in a castle in a room with a canopy bed"

What is your budget? Assuming fairly generous if you were considering Amberley.

There are several posh, castle-like properties (and true castles) in the Cotswold area)

There are several posh, castle-like properties (and true castles) in the Cotswold area)>

yup flanner.co.uk lives in one - maybe he could take you in?

Check out http://www.thornburycastle.co.uk/

Is Lords of the Manor your Upper Slaughter property? -

Lords of the Manor was my reference in Upper Slaughter. I'm now thinking about staying in the Cotswolds area, so I'm open to other locations. The Manor House Hotel in Castle Combe was recommended to me.

For a 4 yr old, some of the manor house hotels will look like small castles--Wyck Hill House outside Stow-on-the-Wold used to be nice, but has changed hands and TripAdvisor reviews aren't very good, which is a pity but there are many others than would have canopy/four poster beds--one in Lower Slaughter and I think Painswick but I can't remember names. Then, for a castle that really looks like a castle from fairy tales--moat, drawbridge, etc., go to Warwick.

Arundel Castle is also the perfect castle - if you go to Amberly at least look at Arundel Castle high on its hill.

Thornbury is a definite possibility. Surprisingly (maybe not when price is considered) they were one of few upscale places I checked out that had rooms available the weekend of June 19th. Thornbury was a little too far when I was considering splitting our time between the Cotswolds and Amberley, but would be a good choice if we're going to stay in the area for 3 or 4 nights.