No one was hurt? That's the most important thing! Sorry to hear...will certainly keep an eye out.
But, I would have to agree with der Geist on this one. You might want to invest in an alarm, especially since these guys (if they were the same ones each time, which may be the case) have learned that they can get away with it. If you add an alarm or a "pseudo alarm" it would certainly make them think twice. The "pseudo alarm" is operated by batteries and is sold in your local hardware store (Walmart sells them too) for approximately $20 bucks for 4. They are about 4-5 inches in length and maybe 2-3 inches in width. They have two parts to them-- both held onto the door/ window by 3M tape. Basically, you have to align the two pieces; one to a stationary / fixed part of the window / door and the other to the moving part. Once the sensor detects that the alignment has been removed by the opening of the door/window a high pitched siren goes off ---- this may help to deter those SOBs that have no respect for other people's property.
Anyway, as I said before, I will keep an eye out, but IMHO definitely start with Blinkwatt's suggestion as to where to look. If they are petty thieves just trying to make a quick buck they may not be smart enough to realize that you would be looking on those sites.
Well, good luck in finding those !*#&@^#@!!! and your wheels!!