Then there was one...

I've only had three hubcaps on my car for the last few years.  One day, the front passenger side hubcap was on my car, and the next day, it was just gone.  I didn't think it was a big deal so I never replaced it.  But this morning, as I left my condo and headed out to my car, I noticed that both hubcaps on my driver's side has disappeared. 

How long has it been like this?  There was a really bad storm last night so my first thought was that they flew off in the 60 mph winds, but now I'm not sure.  Would I have noticed if they flew off while I was driving on the highway?  And here's the most important question: should I purchase new hubcaps for my car or just take off the lone hubcap that still clinging to that back tire? Decisions, decisions...