OK, so reading these comments, I think it'll probably be less-bad than everyone is assuming. Except when the car is first manufactured, things that are close to it have to get there somehow. So lets say you pull up to a tall curb. The Tesla can see the curb as you approach, but then it falls out of view of the front cameras. It still knows where that curb was and, using wheel angle and rotation counting and (to a lesser degree) GPS, the car could theoretically keep very precise track of where it is in relation to things it can no longer see. Same goes for your garage wall. As you pull in, it can use visual cues to figure out how far all the objects are and as you back up, it knows how far its gone and in which direction. It should still be able to tell you how many feet you are from different objects in different directions. If you move something when the car is off and you don't have sentry activated, I guess it probably wouldn't know about those when you go to pull out, but generally we all use those distances when we're pulling in, not really when we're leaving. I'm sure it will be a long time before they get all that worked out and I'd agree this is a parts supply and cost-cutting issue and is definitely not being done to improve things. If they were only concerned about improving the quality of their features, they wouldn't remove hardware until the vision-only version was better than the ultrasound version...which honestly will probably never happen. The radar situation sucks. My car used to be able to tell me if there was a car in front of the car in front of me by bouncing the radar under the car in front of me. Since they disabled my radar, it can no longer do that. It also definitely has more phantom braking issues since disabling the radar. So that was also BS. I will give them that the vision-only driving is now pretty close to how good it used to be with the radar and I'll bet they'll be able to do something similar with the ultrasonics.
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