Guys, the idea isn't to encrypt your whole drive. Remember these are NOT hacker experts. They are normally bored/greedy people exploiting their power for entertainment and a vague hope of busting somebody for CP or being able to copy some interesting toons/movies. Most won't be able to tell whether a drive is using all of it's formatted space or not.
You don't NEED to encrypt everything. All you need to do is present an 'average', boring, laptop. Have a few movies, modest music collection, a few games.
Keep anything sensitive in an encrypted rar or something. Rename the extension.