The only response I can give, which won't really help you but will stop the Ding Ding Bloody Ding, is that "OK so I maybe should" should read - I should. No quibbles, it is against the law to drive without a seatbelt unless
Exemptions from seat belt wearing
The legislation provides for a number of specific exemptions from the seat belt wearing requirements on medical and other grounds. Please consult your doctor if you think you should not wear a seat belt on medical grounds.
As for the others these include:-
"(b) the driver of or a passenger in a motor vehicle constructed or adapted for carrying goods, while on a journey which does not exceed 50 metres and which is undertaken for the purpose of delivering or collecting any thing;
(c) a person driving a vehicle while performing a manoeuvre which includes reversing;
(d) a qualified driver (within the meaning given by regulation 9 of the Motor Vehicles (Driving Licences) Regulations 1987) who is supervising the holder of a provisional licence (within the meaning of Part III of the Act) while that holder is performing a manoeuvre which includes reversing;
(e) a person by whom, as provided in the Motor Vehicles (Driving Licences) Regulations 1987, a test of competence to drive is being conducted and his wearing a seat belt would endanger himself or any other person;
(f) a person driving or riding in a vehicle while it is being used for fire brigade or police purposes or for carrying a person in lawful custody (a person who is being so carried being included in this exemption);
(g) the driver of—
(i) a licensed taxi while it is being used for seeking hire, or answering a call for hire, or carrying a passenger for hire, or
(ii) a private hire vehicle while it is being used to carry a passenger for hire;
(h) a person riding in a vehicle, being used under a trade licence, for the purpose of investigating or remedying a mechanical fault in the vehicle;
(j) a disabled person who is wearing a disabled person's belt; or
(k) a person riding in a vehicle while it is taking part in a procession organised by or on behalf of the Crown."
If of course you fall into one of the above categories then contact your dealer and they will remove the warning chimes for you.