Company cars are not really tax efficient and we often advise clients to buy the car privately and just charge the company for mileage. For one client with expensive taste in cars we even recommended staying as a sole trader rather than a limited company.
This is because cars are treated as benefits in kind and taxed as if you have additional salary. The value of this benefit is based on a percentage of list price (including accessories). The employee pays tax and national insurance and the employer also pays national insurance.
The percentage used for electric vehicles is much lower than for others although this is increasing each year.
As well as the vehicle and fuel for personal use is taxed at a flat rate for the year so work out how much you use to see if it is tax efficient.