Originally Posted by Karlos G

IMO yes very much so!
Even if your car is standard everything is soooo old and could fail at any time, so being able to monitor oil temp, pressure and boost in addition to the normal water temp is very important.
Even more so in a tuned RST where things may be on their limit a lot of the time.
I'm also fitting a water level light so if I burst a hose or even have a small leak I will no before my water has gone and the engine over heated doing the head gasket and who knows what else.