A specialized rental car insurance policy can save you a lot of money. The biggest cost of car rental is most usually the insurance. With e.g. (icarhireinsurance)[https://icarhireinsurance.co.uk] you can get year long rental car coverage for a bit more than 100 GBP.
Cost of renting a car
In many places you can rent a car for 5$ a day. But that's just the car. LDW and CDW insurance can easily end up costing more than 15$ a day. So a dedicated rental car insurance can already pay if you're renting 10 days a year.
Cost of owning a car
I've owned two cars in my life. Both I bought second hand. The first car lasted less than a year, and when I do some rough calculations it's obvious that it would have been cheaper to simply have rented a car for longer periods. Plus I would have saved all the hassle of heading to the garage and dealing with paperwork for insurance and tax.