I had a car broken into once. Smashed a window, took the head unit, some CDs and pried open the back seat to see if there was a speaker box in the back. I was most angry about losing the CDs since everything else was covered by insurance. What was weird about it was they didn't take the radar detector even though they had to move the power cable to get to the stereo and missed the cell phone on the ground in the back seat.
What thieves normally do to get into cars is use a crowbar in the side of the window to try to pop the glass out of place and remove the glass. It's a silent way to get in. The problem is it ends up bending the window frame on the door and you pretty much have to replace the door because it's difficult to fix the bent metal there. In my case they tried to pop out the window, bent the window frame and then smashed the window so there was glass everywhere. Makes you want to just leave your doors unlocked. I used to work with a gal that grew up in a bad neighborhood and she always left her car unlocked so they wouldn't smash the windows.
It might be more common to steal luxury cars and the more common cars like Accords and Civics but when it comes to breaking into cars, older cars and cars that are dirty on the outside or messy on the inside are more likely to be hit. An older or dirty/messy car is less likely to have a working alarm and more likely to have a head unit that can be removed. If there is a bunch of stuff visible in the car it's possible somewhere in the mess is some cash, tools, CDs, cell phones, credit cards, wallets, purses, small electronics, etc. It makes more sense to break into a car that you can tell has stuff to take than a car that looks clean, probably has an alarm and you can't see anything worth taking.