Graham Bishop.com

Insurance Europe has published a checklist regarding the insurance implications of a no-deal Brexit.

The checklist includes:

Motor insurance - Currently, motorists insured in any EU member state can drive their vehicle in any other EU member state. However, as no agreement has been reached to continue this in the case of a no-deal Brexit, both UK and EU motorists should check with their insurance provider to see whether they need a Green Card.
Health insurance - Currently, EU residents travelling within the EU can request a European Health Insurance Card (EHIC) that provides access to healthcare in other EU countries. However, in the case of a no-deal Brexit, EHIC cards will not be officially recognised by the UK for EU travellers or vice-versa. Therefore, travellers must ensure they have adequate travel or health insurance to cover any health services needed while travelling.
Travel insurance - If there is a no-deal Brexit, while travellers from the UK to the EU should still be covered by EU or EEA region policies (with the possible exception of medical expenses covered by the EHIC), both they and EU travellers to the UK should check that their policies cover their destination before they travel.