Hi Rod - on my 2015 petrol Ford Focus, it has an amplified rear aerial - which I put a longer one on (from a Transit van) But Still get some Ignition noise. Worse when accelerating - It's OK around East Anglia, but struggles at extreme distance. Coventry is about it for 648.
It is their older 1,6 bomb proof engine, with a coil pack & separate spark plug leads.

The Old Vectra I used to have, was much better - but that had the sort of coil pack, with a separate coil for each plug. It had a similar amplified rear aerial.

Without the engine running, 648 is just OK at Ross on Wye - away from phone wires of course. This is all Daytime reception of Ground wave.