There is a well known vulnerability, which I will not describe here in detail for obvious reasons, in the cab door locks on the Fiat Ducato / Peugeot Boxer / Citroen Relay. Works especially well with swivel seats as of course once swiveled the buckle is.
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Car Seat Belt Metal Jewelry Seat Belt Accessory Extender For MG HS ZST ZS MG3 MG5 MG6 MG7 GT GS Hector ZX EZS EHS P
Aliexpress UK
Features: -After use, it can be folded, compact and light, does not take up too much space, and is convenient to store and carry. -The inner braided heavy-duty steel cable has excellent cut resistance, saw resistance and flexibility. The outermost layer is a nylon sleeve, which can effectively prevent scratches. -Installation takes only seconds, wrap the lock around the steering wheel and then connect it to the seat belt base, locking both the steering wheel and the seat belt base at the same time for double anti-theft protection. -With a bright yellow casing, it is very conspicuous and can serve as a warning whether it is day or night. Specification: .
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2pcs Car Seat Belt Shoulder Pad Cute Cat Car Seat Belt Shoulder Cover Interior Decoration Accessories for Men and Women
Aliexpress UK
This heavy-duty seatbelt wheel lock is a visible anti-theft device. It is made with durable tempered steel and is a universal fit for all vehicles. The physical and visual deterrence will prevent theft and increase the security of your vehicle, wherever it is parked.
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New beautiful large bow, bling-bling, breathable fabric car seat belt shoulder guard cover, seat belt decoration for women
Aliexpress UK
Features: -After use, it can be folded, compact and light, does not take up too much space, and is convenient to store and carry. -The inner braided heavy-duty steel cable has excellent cut resistance, saw resistance and flexibility. The outermost layer is a nylon sleeve, which can effectively prevent scratches. -Installation takes only seconds, wrap the lock around the steering wheel and then connect it to the seat belt base, locking both the steering wheel and the seat belt base at the same time for double anti-theft protection. -With a bright yellow casing, it is very conspicuous and can serve as a warning whether it is day or night. Specification: .
eBay
Car Seat Belt Extension Plug Buckle Seatbelt Clip Adjustable Extender For Jeep Renegade Wrangler JL JK Gladiator Grand Cherokee
Aliexpress UK
Here we have for sale is a pair of black leather BMW seats with built in seatbelts, fully electric which is just 1 live and 2 earth's, we have had these working on the floor. Ideal for fitting into a vehicle where seatbelt access is hard.
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3inch Car Safety Harness 4/5/6 Point Adjustable Universal Racing Sports Seat Belt Quick Release Nylon Seat Belt with spar** logo
Aliexpress UK
The Single Van Seat with Seatbelt is a convenient and safe seating option for campervans. this seat is a practical and comfortable choice for those looking to add extra seating to their camper. The seatbelt simply bolts to the side wall above the seat.
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Universal Baby Safety Car Seat Belt Pads Baby Stroller Shoulder Strap Covers Soft Car Seat Belt Cushion Pram Shoulder Guard Pads
Aliexpress UK
Features: -After use, it can be folded, compact and light, does not take up too much space, and is convenient to store and carry. -The inner braided heavy-duty steel cable has excellent cut resistance, saw resistance and flexibility. The outermost layer is a nylon sleeve, which can effectively prevent scratches. -Installation takes only seconds, wrap the lock around the steering wheel and then connect it to the seat belt base, locking both the steering wheel and the seat belt base at the same time for double anti-theft protection. -With a bright yellow casing, it is very conspicuous and can serve as a warning whether it is day or night. Specification: .
eBay
car accessories seat belt extender,buckle, seat belt clip,for mercedes-benz CLA CES CLS SLK GLK CLK SLS CLG GLE GLC GLB EQC GLA
Aliexpress UK
Features: -After use, it can be folded, compact and light, does not take up too much space, and is convenient to store and carry. -The inner braided heavy-duty steel cable has excellent cut resistance, saw resistance and flexibility. The outermost layer is a nylon sleeve, which can effectively prevent scratches. -Installation takes only seconds, wrap the lock around the steering wheel and then connect it to the seat belt base, locking both the steering wheel and the seat belt base at the same time for double anti-theft protection. -With a bright yellow casing, it is very conspicuous and can serve as a warning whether it is day or night. Specification: .
eBay
Bicolored Colour 3.6M/Roll Car Modified Seat Belt Webbing Car High-Strength Polyester Seat Safety Belts Car Accessories
Aliexpress UK