Discounted vehicles do seem to pop up, and not just at quarter end. I found two different Mid Range models in April, took delivery of one a few weeks ago. One had 5 miles and a $2500 discount. The one I got had 100 miles and was a Dec '18 build for about $3500 off. I had my OA confirm it was not a showroom model and had no notes on file of any defects or delivery rejections. It was presumed it was test drove briefly or something given the miles on it. The final MVPA stated "Previous service/demo vehicle".
It amazes me several-months-old vehicles pop up... geez, a July '18 w/ low miles was still around until now?!
I would be cautious if you find one; make sure the discount is worth the risk of anything being wrong with it. In my case, my car was cosmetically great, but it turns out the side repeater cameras weren't working properly. Tesla should've known about this and fixed it before delivery IMO. I didn't of course notice until after driving away at delivery. If I take a pessimistic view, I could believe Tesla had this car intended for use as a test drive unit, but given camera problem, they pulled it, and then sold to me w/o acknowledging this known defect. But it's impossible to know the exact circumstance, so I'm just hoping it gets fixed (still waiting on parts) and I can move on.