Do you mean "J"? (Tesla VINs start with 5YJ).
However, I was curious... now that I have a VIN and it's clearly displayed on my order page, I thought I'd check the source, searched on "5YJ" and got nothing(!) I'm not sure how that works -- I guess the VIN may be getting displayed based on a dynamic call that doesn't actually write into the source(?) I haven't analyzed the source (and while I work in software, I'm definitely not a web/HTML guy).
The Firefox plugin that's been shared here does display the VIN as well, so the folks who wrote that are able to see it. Maybe I'm doing something wrong, but whatever I was doing prior to getting my VIN would not have found the VIN anyway.