About 15 years ago we had a family holiday to Shetland (don't know if you'd count this as a Scottish Island). Drove up to Scotland then parked the car at a friends house, and train to Inverness for the ferry to Shetland. We had two touring bikes each with an original trailerbike hitched up behind. (My brother and I were 8 and 5 at the time), and a grand total of 6 panniers between us. Rode pretty much the whole length of the islands, using the ferries, from a base at a cottage near Lerwick. One of my most treasured. Childhood memories. Very few cars, but I can't remember what the roads were like really, just the lack of trees!