they don't supply it because in places where the car is RHD, you don't need it. Same reason why if you buy a filter tree for some reason, it doesn't come with the plug for where the LHD sender goes.
Later
"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut." - Albert Einstein
When was the last time you *really* did something with your Z to call yourself a Z enthusiast?