Nice try with the tyre example but it does not count as a customising item, although with the number of companies producing tyres it does give the buying public a varied choice.
So let me change tyres for shoes, you go to a cobbler and have hand made shoes, these are custom made, although there may be other people with the same style of shoe, theirs are from a mass producer of shoes, yours still remain custom.
Be it home produced or mass produced once the initial item has been manufactured, it then becomes easier and quicker to produce replicas if this is the desired route.
However if it is home made and mass producers see that the 'trend' is to follow the style of the home produced item then they are more likely to cash in on following the trend as they are in the habit of wanting to make money.
Take OCC for example, they started out as single item customisers, eventually the customer base was / is for their mass produced take on custom choppers, along with other American chopper builders. From this 'trend' the Victory motorcycle is available with various twists, thus a 'trend' becoming a mass produced motorcycle. Hence in my way of thinking the future of motorcycling, custom becoming production, following a trend.
Lets just say the bikes and trikes were built for those I thought deserved them, my reward was not monetary.
Yes I could of made it pay but then the pleasure would of been lost. I am no longer able to continue due to my own ill health. (attached a picture of my own lowrider built 20 years ago, a box of bits to what you see in seven and a half weeks, what wasn't in the box I made).
As for the Jaguar bike, IT, I agree will remain a true one off custom, as will many others I'm sure you see on the streets in America if you are still there, However there are many that inspire the designers and manufacturers to follow what they see on the streets world wide.
You have a nice day now