I've discovered, or rather, a passenger has discovered that someone has been sick on the seat belt, then hid it by putting the seat belt back. 

 

Otherwise no visible sick in car interior. The person who booked the taxi has now been barred from the taxi firm. 

 

But still, how do I properly clean a seat belt system? 

I'd say some mild soap and water and wash it down with a soft cloth. Don't use anything harsh or abrasive as you could damage the material and reduce its strength. Pull it all the way out of the reel and secure it while you're cleaning it, and leave it pulled out until it's dry.

Screw the mild soap and kid gloves, a bucket of steaming hot water with biological washing powder and a girt big scrubbing brush is what you need.

 

Rinse it and leave the belt extended until its dried.

I'm in the middle of a shift right now. Just washed the whole thing with water and sterilising spray along the entire length of the seat belt. 

 

The problem now is the drying bit?? If I left it outside the car for hours I'd be losing a lot more money than the time I just spent to clean it. 

 

It'll last the night wet right? 

It wouldn't be ideal to let it roll up wet, but try not to leave it that way for too long. Mildew is a risk, as is corrosion of the mechanism. A dehumidifier and fan heater will help speed up drying.