The first indication of a match (an assignment of a vehicle to your order) has been the ability to find a vin in the source code on your Tesla account. However with the latest version of the Tesla app the vin is shown there. If you log into to your Tesla account and click manage order so that you get to the overview page of the order you can right click (on the page not the image of the car ) and select view source code (with chrome anyway ) . You can then search for LRW ( the first three characters of a made in china car as are all model 3 for UK) . I'm not sure at what point the app updates as this change occured after my order was already completed. If my instructions are too brief you can search in the forum for find vin. There are many other posts detailing the process. There is also a YouTube video , what a surprise
, explaining the process, however that is based on Fremont made cars. All UK model three currently come from china (referred to as MIC) and all of their VINs start LRW