In my experience, you can. I had a loan and also wanted to pay the rest through my bank. I showed them the pre Approved loan document and was asked to pay the rest via my bank but I asked to see my vehicle before marking that payment. I inspected the car and was satisfied with it, I went back inside and used one of their computers at the Deivery location to long into my tesla account and made the payment via my bank account info.
Assuming you’re paying it off, you can ask to inspect the car before signing the papers.
I even had some changes that needed to be made to the MVPA and they made those changes at the same time of delivery, I just had to wait a little bit for them to get the updated paperwork but I was out of there within an hr and half due to the paperwork updates.