or go with a insurance company (normally c.i.s) which lets u drive another car as long as its not registered to you, buy a 50 quid 950cc fiesta, insure that, buy a cossie, register it in your mates or parents name and there u go.done it for years.
this only works if the registered owner has a valid insurance certifacate for the car and is technically fraud.
Also if you had insured your car and not disclosed what mods/engine was in it i'm pretty sure the insurance company would take your money laughing as its as goood as burning it if you were unfortunate enough to have an accident!