BÅsÅ is short for Bosozoku and refers to Japanese youth subculture associated with customized motorcycles. The style usually involves putting massive spoilers and 8 exhausts onto cars and looks sick. The whip refers to a car or motorcycle. So to 'Boso The Whip' is to add sick/ridiculous Japanese mods to a car, motorcycle or other form of transport.
Aye come lad let's BÅsÅ The Whip it's looking like a shitbox at the minute