I did the same thing 2 days ago. Found a test drive model for crazy cheap P100D 2018 build w/FSD. 3k miles on it but heavily discounted. Waiting for pics to make final decision. It’s considered new so I’ll still get fed deduction. Def good decision to go with 100D.
If you buy new and it’s delayed you may lose 1,875 bucks.
Be careful on waiting for the pics coz you may lose the car, someone else can just place their order on it, I know coz this happened to me, I waited for a call back and waited to decide on it due to some negative stories I’ve read from threads and next thing I know when I spoke to CS, the car’s been sold already.