The automotive escape hammers with the pointy spike won't do much to get you out of a GA aircraft with a plexiglass (acrylic) window/canopy, and is useless for those which are lexan (poly carbonate). They work well on auto glass, other than laminated windshields.
If you want to break a plexiglass window, an axe is your best hope, though in truth, there's not so much room to get a swing at it from the inside, particularly with a passenger in there with you.
A trick which works for the majority of single Cessna windshields which do not have the center strip, is to kick out the whole windshield along the top where it meets the roof line. A few Cessnas may have a few bolts along the roof skin into the windshield, and they'll be really heard, but otherwise most Cessna single windshielda are held in be air pressure, their fit in the sealing felt, and the two wing root fairings. If you're motivated enough, you may be able to kick your way out along the top. Once the top is out, the whole windshield should mostly pop out of the side door post and glareshield trim strips. For Cessna pilots, have a really discerning look at the edges of the windshield, and you may find that there's not as much holding it in as you think.
Otherwise kicking out an opening door window will be your easiest, if fitted, that arm which should hold the window partly open, should break off.
For Piper Cherokee, and other types which have the little vent window in the pilot's side window, you'll find that the window will crack the length if kicked at the corner of the vent window hole. You'll still have to work at getting the broken bits of window out of the frame though.
Often around airports, there are derelict airframes, find one like yours and study the window and windshield installation. If you can get permission, try to break one.
For your car side and rear windows, the very best and most simple tool is a spring center punch. Easily available at a hardware store (iron monger?). Try to punch on the etched writing which can usually be found in a corner of the glass. When you buy the punch, practice on something of no value to get the hang of using it.
Avoid trying to use the car windshield as an exit if it's laminated. They are really messy to kick out, and will produce lots of glass dust, which is nasty. If we must get someone out through a car windshield, we'll saw it. To control glass dust, we spray the area to be sawn with shaving foam, which we carry on the fire truck for that purpose.
If you're going to break glass, and there is anyone else around, yell "breaking glass" just before you do, allowing enough time to hear and react to someone who might say whoa. Side windows will burst quite a distance when broken from the inside out.