Advice regarding insurance for modern classic (BMW 316i Sport Compact 2000)

Hi All,

I have just realised that (on paper) my car's value has depreciated to zero, (even though she's still in good condition). She has and has always had full-comprehensive insurance through the AA (Automobile Association), now approaching 14 years NCD.

Should I be "worried" about driving a zero-value car from an insurance point of view?
Can you recommend any other insurance companies I should be speaking to and what questions I should be asking them?
Is it time to take her off the road?
What do other owners of similar cars do for insurance?

Thanks for your advice,
James