I know it is not an offered option, but if you could - would you? I am original Signature Model S owner and would never part with my little part of history, but have to admit that I'm a little envious of the new features. Plus, until 7.1 comes out, I will likely have a big reminder that I don't have AutoPilot on my dash as I watch static picture of the car with no sensors...
Would you pay 10k for a sensor retrofit? 15? 20?
Just curious.
Pick up a CPO that has autopilot features.
Edit: Ah, I see you have a signature model. Well, the Model S has undergone a lot of changes. Picking up a VIN # that is over 50,000 past yours is actually a very different car. But with a sig? I would switch to a newer CPO rather than upgrade for $15-20k.
My P85 is worth about $65k now. (sigh)
A new 85D with my features + autopilot is $98,250 + $1,200 - $7,500 or about $92k (but doesn't include dual chargers)
That's $27k difference. But then, that's a new car with very few miles, reset warranty, autopilot, and all wheel drive. It has higher range, faster performance, and a new battery. $20k would be too expensive as it would be worth it to buy a new one instead. I suspect $10k is too low in terms of cost of upgrade. It's likely more like $15-20k, so it probably won't work out.
The cheapest P85 with autopilot at CPO is $87k (after credits) which is a difference of $22k. It has more features than my car, so the actual difference is less by about 4k, so the diff is $18k. That's tough to pay the upgrade cost.