I see a lot of the DRL problem. If you come out of London on the M3 or M4 both are well lit for a good distance out of London. During this time the cars lights remain dormant even if they are automatic-on/off. DRL's are on (front only) so making these cars stand out from behind.
When you get to the unlit lane the automatic cars light up, the others usually wake up and switch them on! Usually.
