OK, hold your hats folks, here we go: I've tried to get in as much as possible whilst being nearly sensible about what's achievable (Outer Hebrides/Orkneys/Shetlands - not, sorry, but have put in some Inner Hebrides!). Outraged "you can't go to Scotland and not go to (X)" amendments and suggestions will almost certainly be met with sulks if I don't get to do Skye and Glencoe, but I'm easy about the rest of it ;P
This route is reckoned by Google directions to be about 40 hours worth of driving total, which seems about right, taking into account a) that there can be detours for some more hair-raising driving than much of the below route b) some fitter-and-younger-than-me people want to do some Munro bagging. Et cetera.
So - listing main roads only:
Sun 23 Jun** - late afternoon. Starting point is Gretna Green. It won't be getting dark until 11 pm so plenty of time for photos.
Gretna is vile. Depart via A7, overnight somewhere around Hawick - 40 miles
Mon 24 Jun: From Hawick: A707/A72 to Selkirk and Peebles (great place name)
We're still not in proper Scotland yet IMO, and have to get past Edinburgh somehow, the only way is motorway, get over it - at least the Forth Bridge is famous and therefore interesting: head up A703/701/702 to A720/A90 to skirt round Edinburgh, then up the M90 to Perth. Now it starts to get good: A93, until you see mountains. Those would be the Cairngorms. Head north on the A939 from a metropolis called Crathie, and suggest overnight at Speybridge (Grantown on Spey). Total for the day: 200 miles, about 5 hours driving.
Tue 25 Jun: Anyone who cheated and skipped ahead will notice that I have omitted the eastern bulge (Aberdeen etc) because of limited time and my excessive fondness of the west side of Scotland. So let's have today as a free day to go to Aberdeen for those who actually like it/climb mountains/find the stupidest conceivable road to drive on/visit a whiskey distillery and campaign for Home Rule for Scotland so it turns into Abroad and we can buy single malt duty free - whatever. We're also easy distance from Aviemore and Loch Ness here (and in fact later. There's a limited choice of roads in Scotland.)
Wed 26 Jun: A9 to Inverness and points north: switch to A99 for John O'Tourist Trap Groats (or Cape Wrath EDIT: no, not Cape Wrath, that's the other end - whatever the other lighthouse is called ...), then scoot along the top - A36 to Tongue, and suggest overnight here. Approx 215 miles, 5 hours driving.
Thu 27 Jun: Just drive round the outside. Don't turn right, your car will get wet. A838/A894/A835 (Ullapool)/A832/A896/unclassified. Overnight at Applecross. Approx 210 miles, 5.5 hours
Fri 28 Jun: Now for the *really* good bits - if you're me anyway. Rejoin the A896 from Applecross, head south on the A890 to Kyle of Lochalsh ... and Skye.
"Fair these broad meads - these hoary woods are grand;
But we are exiles from our fathers' land.
From the lone shieling of the misty island
Mountains divide us, and the waste of seas -
Yet still the blood is strong, the heart is Highland,
And we in dreams behold the Hebrides."
Sends shivers down my spine that does (Canadian Boat Song, attrib. Anon if anyone wants to Google for the whole thing).
Anyway, take the A87 to Portree, then A855 to Uig, and rejoin the A87 until junction with the A850. Take the A850 and loop round back to the A87. As the Kyle of Lochalsh closely parallels Gretna for beauty and charm, suggest overnight at Dornie. Oh, I should disclose at this point that I have NO IDEA about facilities at any of these overnight stops, I've spent most time on the islands or based in Inverness/Aviemore/Fort William and scooting round the Highlands from one of those bases. Total for today - about 190 miles, 5.5-6 hours.
Sat 29 Jun: A87, A887, Loch Ness, A82 (Glencoe
), A85 to Oban. It's pretty. A816 to the poetically named Lochgilphead (which sounds as unromantic as pilchards or haddock, but I'm sure it's very pretty). Up the A83 (Inveraray) and rejoin the A82 at Loch Lomond, overnight here. 200-and odd miles, 5-6 hours depending on where on Loch Lomond people want to overnight. Somewhere where we can all go 'oh shit, where's the nearest newsagent, it's Paul's birthday.' Near a lifebelt in case Mat decides to go swimming.
Sun 30 Jun: I've now lost all interest because we're going to be leaving proper Scotland and going home
** I would actually really love to bring this forward a day and start Sat 22 Jun late afternoon which means we would hit Skye on Thursday, then stay in Broadford and spend Friday on Skye/round the Highlands. This would add only half an hour to Loch Lomond run on Sat 29.