yes I dont think that range would be practical, as still you have to plan where to refill as not all stations have LPG.

Even with the 90 litre tanks, I only get a range of around 250 miles, and as it uses petrol for start up and warm up, you'd still use the small petrol tank full pretty quickly.

In the saloon, to be honest, the remaining boot space I find absolutely fine - bigger than you think! But I can see it wouldnt be so neat and defeats the purpose in the estate