I drive as many as 3-5 different vehicles most days. Mostly HGVs and note which stations their radios are tuned to. I have never discovered a single one tuned to Radio 4 on LW.
Most are tuned to non BBC stations and the rest to Radio 2.
It is a pity that LW is being degraded in an attempt to make it unservicable to us vintage guys but I fear it will not be long before it vanishes together with MW transmissions.
I have lost my interest in vintage radio due to the lack of middle of the road stations on MW/LW. At 69 I am far too young to get involved with Radio 4
Regards, John.