There is a good article written in 2016 about Jim Clark's 1966 RAC Rally in NVW241C on the MotorSport Magazine Online website, see
http://www.motorsportmagazine.com/opinion/rally/jim-clarks-1966-rac-rally
Don Barrow, who also competed in a mk1 Lotus Cortina in the same rally, tells the story from when the police helped Jim Clark through the traffic in Glasgow to make up some lost time (apparently the police stopped a few other rally cars as well to let him through), see
http://www.donbarrow.co.uk/autobiography_stage2.html
(scroll down ca 3/4 of the page)
Also, Nigel Raeburn who was co-driving for Richard Hudson-Evans in a Mini on the rally, tells the story about when they passed Jim Clark and Brian Melia, sitting on a bank at the side of the road, their Lotus Cortina "so far off the road it was out of sight".
RHE stopped by a phone box and reported the news to BBC Radio who broadcasted it, before rally control even knew they'd gone off the road again.
See
https://nigelraeburn.wordpress.com/2016/11/04/jim-clark-and-the-1966-rac-rally/