I've been around the loop with Tesla trying to move this forward without any luck. I have a custom order which had a Sep/Oct delivery date but now showing Nov/Jan in the app so I decided to look at existing inventory and found an exact match in my local sales center. Tesla refuses to add the VIN to my existing custom order saying I have to create a new order, seems completely nuts. Also, I can't go look at the existing inventory until I place the order, my concern is that the existing car may have issues so I will have to reject and end up with 2 orders!
@PatriotOne If the car is truly at the deliver center, most likely you can just show up, find it on the lot, and take a look from outside the car with nobody stopping you. I haven't done that myself but I've seen MANY reports here of people doing that, complete with photos. Of course maybe some delivery locations have secured parking, but for sure many don't.
For what it's worth, I think that's a valid concern and I had the same concern about our inventory car.
Now as for getting an inventory car assigned to an existing order, our local Sales Center staff did exactly that for us last year. When we placed our order they actually suggested it as a way to get our car sooner. They said the config doesn't even have to be an exact match, e.g. the paint or interior colors can be different at least, maybe more.
Sure enough, when I looked online a few days later I spotted a config we wanted (exactly matching our order, as it were, though we were flexible on the interior color), I called them up (local Sales Center), and the Sales Advisor who answered immediately understood what I was asking and jumped on assigning the inventory car right away. She wasn't even the one who had suggested this to us. I believe all the Sales Advisors at that Sales Center were aware of this possibility.
The inventory car was listed with FSD enabled but that was no problem, the Sales Advisor removed FSD as part of assigning it to our order. It never even showed FSD once assigned to us. (At that time they seemed to be listing every inventory car with FSD enabled.)
We definitely never paid a second Order Fee. I checked all of the numbers and line items carefully on the MVPA, everything was exactly as I expected, and we paid via Cashier's Check for the expected amount, no more.
However, that was almost a year ago! Policies can change. Maybe this truly isn't allowed anymore. Also, the Sales Advisor who assigned our inventory car gave a strong hint that if there had been a price increase after our order, then assigning an inventory car might give us the higher pricing. In our case there hadn't been any price increase so that wasn't a concern.