When someone dies you will need to contact a wide variety of organisations to inform them of the death. Here are just some of those you may need to contact, you may have to send them a death certificate:

vehicle registration
driving licence
passport
motoring insurance
motoring breakdown policy
household insurance
life assurance
pension plans
bank
building society
credit card companies
utilities (gas, electricity, water, telephone)
employers
council tax
benefit agency
income tax
mortgage
internet provider
child(ren)s school or childcare provider
doctors
dentists
hospital clinics
private health care provider
solicitor

It is important to note that if the deceased owned a vehicle then it may be no-one now has insurance cover to drive it.
Many policies state that a vehicle may be driven by someone else with the owner's permission but as soon as the owner dies any such permission may cease.
Contact the car insurance company before anyone drives the vehicle to make sure they are covered