Keep up to date with the FCO travel advice as travel to some parts of Kosovo may be inadvisable and, note, that to travel against the advice of a government agency will often affect travel insurance.
If renting in winter months (typically 15th November to 15th March) your hire car should be equipped with winter tyres. Although charges for winter tyres are often built into the hire rate shown, it is worth checking as it isn't universal.
It's quite easy to find car rental packages that include the first additional driver for free which can be a major saving.
Car hire excess charges can be high in Kosovo. We've seen an excess of €2875 on a small family car. The excess can be easily covered with a policy from our car hire excess insurance comparison service, though you may wish to look at policies covering excesses of £3,000 or more to be sure to cover the excess.
If you want to hire a car in Kosovo and take it out of the country, you will have to shop around. Cross border travel is often allowed with additional charges for insurance but there isn't great consistency over which countries you are allowed to visit and which are prohibited. This does at least mean you can probably find what you need.
For example, Hertz allow travel into Albania, Macedonia, Montenegro, Bulgaria, Croatia, Greece and Slovenia but you can't travel to Serbia.