Stop for a wee Snack.

[Dai37]

Just a suggestion that we have used a number of times , when on a journey and starting to need a break. Try looking out for local golf clubs. They have the advantage of usually ample car parking, and welcome non golfers with good value food, drinks and toilet facilities.
A few that come to mind are Derllys Court golf club just off the A40 at Carmarthen and Machynys golf club at Llanelli, another at Newport pembs, the last two have spectacular views. And a friendly and inexpensive welcome at Derllys.

 

[RobbyMClark]

Aberystwyth golf are apparently offering overnight @ £10.

 

[bridgedino]

We just hunt down a decent lay-by. Everything else is on-board

 

[KiwiKampers]

I have often wondered why so few golf clubs in the UK offer park-over sites.
It could be a nice little earner for them, plus they would have overnight security provided by the motorhomers.
We use golf club car parks quite a lot in NZ, and also Yacht Clubs. They always have water available and the club house has showers, toilets, rubbish bins and a friendly bar.
There are some that have installed EHU for motorhomes and you can pay on-line or put cash in an iron maiden if you arrive after the Club has closed.