Get it in writing. Ask them for ‘paperwork’ (either on headed paper or as an email attachment) detailing the Model, Options, and all the things the car should come with. Then you can check regarding the tinting, and should it arrive without you’ll have physical evidence to support your argument that you asked about the tinting right from the start. (The ‘paperwork’ for my latest car came as an email attachment, but still had all the details.)
And keep all email messages to and from them for the same reason – so you can quote dates, times and exact words should there be any issues. Stick them in their own file so you can find them easily if you need to.