That's a really good price for that car. Did they give you a Carfax? If not, go to the Carfax page:
https://www.carfax.com/Service/garage
And set the car up under my vehicles. Once you set it up, it will show you the entire history that's available. If the previous owner serviced at the dealer, you'll see everything that was done.
As for the radio screen bubbling, a new one is over $3000 from BMW but there are aftermarket versions you can get for much less that will include Android Auto and Apple Carplay. I got mine from Euro Style Tuning.