EIM23485 | Car and van benefit: pooled cars and vans: inadequate parking facilities
From HM Revenue & Customs · Employment Income Manual
You will sometimes see it argued that a car or van that would otherwise qualify as a pooled car or van is only taken home at night by an employee because:
there are inadequate car parking facilities at the employer’s premises, or
if the car or van were left overnight at the employer’s premises it might well be damaged by vandals, etc.