Hi all.
My 2 pence worth.
As I've got full harnesses I had the same issue and in my personal experience there were a number of ways around it that I could take.
1)Code it out (as pointed out above but difficult/expensive maybe?)
2)Plug in another seatbelt clip into the catch (can't use the catch when you do want to?)
3)Find and cut off the buzzer/replace buzzer with an LED (low tech, solves the annoying symptom but the rest of the airbags may not work when needed?)
4)Take apart the catch and investigate where the car gets its "clicked" signal from and bridge it (not tried it myself, possibly play with a scrap one first?)
In my case when I use the harnesses I lead the inertia reel belt round the back of the seat and engaged so the system is all happy and the rest of the air bags still work. That was just what worked for me.
As a "newbie" I feel that a number of you have been a bit harsh/judgemental etc etc (i'm guessing this is why there is a sticky asking us all to play nice?)
We are not all lucky enough to be sinless, born-omnipotent experts in all fields. (I still have to check the diagram on a plug when re-wiring one!)
I always imagine forums like speaking to fellow enthusiasts at a meet, if I pluck up the courage to ask a question or voice something im not sure about and I get shot down, ridiculed or read the highway code i'm probably not likely to go back there.
But if I get a helpful answer followed by a bit of guidance, hint or "but in my opinion" that meet would quickly become my favourite. So when I have finished my project, or bought a hot new car, or have some parts I no longer need where do you think I will be going first?
Like I said, just my 2 pence worth.