Hi Dec
It is straightforward in theory, but fiddly in practice!
There's a good description + pictures here:
la4ldesylvie.fr/index.php?option=com_content&view=article&id=323
A Renault 4 in Dover? That's a new one on me.
Dec, In that case she must be the R4 I saw advertised a while back from the St.Margaret's area. Welcome to the forum and we must meet up some time. My wife and I took a day trip to Boulogne a couple of weeks ago so would have passed by you. You may not be aware but there are half-a-dozen R4s in Kent with a biggish get together in May at Hole Park near Tenterden.