Do any fellow car enthusiasts have recommendations for tire pressure monitoring systems? How can I upgrade to automatic locking?

I modified the side mirrors to fold in, with window closing when locking the car and auto-locking features.

You need to add a module for tire pressure monitoring! For automatic locking and window closing functions, you just need to buy an OBD window closer.

Which one? After 2021, you can directly add a module for over a hundred to display on the dashboard. For 2018-2020 models, you can only add a small screen in the lower-left button area. Automatic locking can be programmed at the 4S dealership; some do it for free, some charge, and some don't offer it at all. You can also achieve it through an OBD box. Some third-party options also include features like mirror folding and tire pressure display.