If it's purpose is for advertising I can see why it's required, but it just seems a lot of faff for nowt otherwise.
I don't know much about the M3W specifically from this point of view, but to respray a car like my McLaren would be £15k, whereas a wrap is £1,500 on, and £200 off. £1,700 is a lot less than the £30k two-way respray.
What would a respray of the M3W actually be? Can it really be done inside £1k??? (Certainly not two-ways)