You can put car expenses through your business accounts e.g servicing; petrol & best tax saving of all is depreciation every year. Financing the car should be done in the most financially efficent way i.e as in to not pay interest at all or much interest. In that respect paying outright is best, no interest to be paid out. But if this large capital sum could be used elsewhere to earn more than what you would lose if paying out interest on i.e. a loan to finance the car, then it would be better to get a loan.
E.g. monthly repayments 6% & use the large capital to invest e.g a property, -increase in property value 10% = very approx 4% better off, (or in your case investing in other cars stock)