Advert on company car

One word answer: No

... a fire engine with the word "FIRE" painted back to front on the front of it, then there's no benefit, unless the private use is significant.  So no putting fires out in your spare time you naughty boy.

In pretty much all other circumstances, I'd agree with Cloudcounter.

I would allow the cost of putting the advert  on the car though in the company accounts if that is any consolation....

Ah, but would you add it to the cost of the car and accessories for P11d benefit purposes? 

Not a serious suggestion, btw, but I wonder if there's a P11d inspector out there who would try this.

To be an accessory, the item needs to be "equipment".  The dictionary defines "equipment" as "the necessary items for a particular purpose".  These car wraps seem to me to be completely unnecessary.

On this topic, they ought to be experts as they always seem to cover their nice cars with yellow signwriting.

By that logic, a very expensive sound system in a company car would escape charge as it could not be regarded as necessary to the employee's duties.

Helpsheet 203 talks about accessories. None of the items listed specifically exclude the car wraps which I understand can cost far in excess of £100 and are fixed to the car (not sure how "fixed" they need to be though).   

My comment was intended to be tongue in cheek, in the spirit of the further question posed.  I didn't say the item had to be necessary to the employee's duties, but necessary for a particular purpose.  I was simply offering my opinion that they're not necessary for any purpose.  The purpose in mind (ie advertising) would be far better served by other means.

Sorry, the humour was too subtle for me to pick up on after 31st January.

I don't see the point of it either aside from drawing attention to the fact it is a company car and so extending an open invitation to the no win no fee parasites to stage an "accident".