Hi Brian,
There's probably going to be an abundance of diesels available, given the way UK Government is going. Not sure about LPG. Auto trader is a good start.
This example shows availability from London, but within 40 miles.
https://www.autotrader.co.uk/car-search?postcode=w45rr&radius=40&make=BMW&model=X5&include-delivery-option=on
A !Removed! extension, or not, enjoy...