Does anyone know if its possible to lower the rear of the coupe, (I think the front is low enough) without compromising ride quality, currently have Bilstein shocks all round with standard springs......

yes, its perfectly possible - just fit shorter springs

As to whether its actually desirable or even safe, I'm not sure

We already know that an uprated rear ARB on its own can turn the Coupe towards oversteer - harder springs on the rear could have a similar effect

I would also think that uprated springs at one end only will make the car handle weirdly over bumps and undulations

Personally, I'd recommend doing all four corners

Cheers Nigel, i'll leave it be then I think........