Our Model S does not have air suspension. When we are parking head in, the ultrasonics do not detect curbs high enough for us to hit or scrape on. And for some reason, perhaps related to the nosecone on the front, it's pretty difficult to estimate when we might hit the curb. We've scraped the paint more than once because of this. Is it normal for the ultrasonics to not see curbs, or could we have a maladjustment? And are there any tricks you have for cozying up to the curb without hitting it?