Either check the potential buyer has third-party cover to drive other vehicles (ask to see policy and proof of ID) if you're happy to accept that or, more simply, you drive.
Check with your insurance, as advised above.
You may have to drive: the owner drove the Motorhome that we bought privately, OH sat in the passenger seat & listened & looked. Obviously, you’re not going to give your keys to someone & wait for them to come back.
If they have it on their policy Driving Other Cars (DOC) cover will give the buyer third party cover when driving the car. It won't cover damage to the vehicle should they be involved in an accident during any test drive.
DOC is however being withdrawn on many policies, so you need to check it is in place.
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