No, no, no, no no, please no.
Don’t forget other than car parks Loch Lomond and the Trossachs does not allow WC between April to October.
Start off as I said in the Mull of Galloway it’s really nice down there, ignore the silly no overnight parking signs that Dumfries and Galloway put up. New England Bay and Port Logan are great, and you can get freshwater and empty your cassette at NEB. Also you could have lots of fun with your kayak in Luce bay. Then head up to Stranraer a nice town and you can park in the car park there. Then head for a cracking Aire in Kirkcolm were we were this year. The pitches are enormous were sea planes used to be kept. Book in advance and you can empty your toilet and get freshwater there to. Then start heading up the Ayrshire coast to Ballantrae, there’s a nice carpark with places for motorhomes. It’s £10 a night with toilets but no services. Continue up to Girvan and again you can park for £10 a night in large motorhome parking spaces, you can empty your cassette there and get freshwater. Then you could head for Largs and get the ferry over to Millport, there’s an Aire there or continue up to Troon and head over to Arran. Then take the ferry from Lochranza to Claonaig, and there are options aplenty. You could head for the Gigha ferry port in Tayloan there’s an Aire there with freshwater and elsan point. You could now either head over to Gigha, or head north and head for Oban and then on to Mull. From there you could then get the Ferry from Tobermory to Kilchoan in Ardnamurchen. From there Scotland is your oyster Barry. But take my advice avoid Skye like the plague, we only go there in winter when the madness has subsided. Also as I mentioned you could head east there’s lots of places there, and they don’t tend to be as busy as the west.