Ground Clearance issues--Will it scrape all the time?

I drive mostly on the I-10 between LA and Phoenix. I hit a piece of tire about the size of my wallet (pretty small, eh). Left a nice paint scrape along the rocker arm. I always park at least one foot from any curb to avoid incidents with the chin spoiler. My '92 Firebird was the lowest car I ever owned. I was constantly hitting the front of it on curbs as the nose of the car was very long.

 

My 2006 Prius has had lots of scraping problems. I live in Florida on a dirt road that isn't at all 'groomed'. I'm ok with no passengers or just my three Labradors in the car, but when I carry a human passenger along with the dogs, there's a root in my driveway that hits. There are also a few driveways in town that I can't enter without a crunching sound.
If you have sugar sand or roads that develop ruts, I'd say be wary of getting a Prius.