Yuh, SWMBO snapped that pic from the copilot's seat. I believe both cars were crawling at about 35mph when we met up, timing it for a slight widening of the road (on the right side of the pic). Perfectly normal, for here.
Despite the 60mph speed limit (quite reasonable for a local), the best I ever dared that day was 50mph on those stone-walled tunnels.
Later, going through a small village, we almost became part of a complete deadlock at a 90 degree corner, with a bus coming the other way, and the other rental ("tourist") vehicles in front not leaving it any space. Five or six other vehicles on the bumpers in both directions cemented the jam. We curb crawled onto a side alley and left them all there.
Here's a photo of another similar scene we encountered. [EDIT] There were NO parked vehicles in this scene! [/EDIT]

Cheers