Are you dead set on having brand new? We always buy one a few months old which has done its huge depreciation already.
I would think mortgage would your best bet, and then overpay on the amount so that you aren't actually paying for it for the next 20-odd years. I bought my car cash in the end but we did look into financing options. Ballon payment seemed crap, you are paying a new price for an old car essentially.
some car companies offer good finance deals ecen 0% apr if you have a big deposit. The only problem with getiing a car on credit id that the loan amt is greater than the value of the car as the depreciation is massive in the early months.
It really depends whether you are the type of person who will keep the car for good or plan to change it every three years. If the latter then normally the finance deals offered by the dealer are best value as they heavily discount the apr in order to sell the cars. With HP and PCP there's also the option to just "walk away" after you have paid half under the halves and thirds rules if the payments are too great or you're in negative equity. The payments would be lower than with a loan if you hand the car back at the end rather than pay the balloon. PCP also gives a guaranteed future value for the car.
If you plan to keep it then using your mortgage reserve would have the cheapest apr, but you would pay more in the long run for the car, unless you are disciplined enough to pay it back at the same rate loan payments would be.
Bank loan is the most straightforward, but the aprs are shocking at the moment.
Paid cash for mine, but it was only £7k. DH bought his through a scheme at work, it cost about £60k and payments were about £800 pm which was bloody ridiculous in hindsight, but it's still going strong 12 years later.
I normally avoid any type of borrowing, would rather save for an old banger.
We just bought a 60 reg car - looks and smells like a new car, has under 10000 miles on the clock, less than a year old, but we paid 2/3 of the brand new price. Traded in our old car, 50% cash deposit, 0% interest on the rest over two years. As a nearly-new car it's not MOT eligible for two years and is still under warranty - I would hate to have been the person taking a £5000 hit after 10 months!