06-01-2020, 10:41 PM
(This post was last modified: 06-01-2020, 10:43 PM by Peter Naulls.)
I remember some experimental version of this 40 years ago when being driven to Scotland in a Morris Traveller (A1 I think). Not musical, but noisy enough to stop you sleeping apparently! I suppose it was a variation on the kerbside rumble strip idea.
Peter.
Peter.