Got fully comp insurance but police seized a new car I was picking up because of no insurance

Many fully comprehensive car insurance policies allow you to drive another car with owner's permission. However the car you'll be driving need to be insured in the first place, otherwise you can't drive it.

People don't usually find themselves in this situation because they borrow cars from friends or relatives. Once they've got the consent of the lender, they can drive the latter's car on third party insurance covered by their own fully comp policy. This excludes car which are not under any sort of car insurance cover though and you should always check that your current policy allows you to drive other cars as well.

So essentially the police are right in this case because you've been driving a car that wasn't insured. It's just unfortunate that you didn't know any better though.

yes and no, Yes u have done the right thing by doing your insurance and No because you should have insured the car before you went to pick it up. If there were to be an accident at the time you were picking up the car u wud NOT be have been covered. Zee. SPINEX