I still use slim jim's to open cars for people all the time. Chevy trucks/suburban/tahoe's are a piece of cake...locked my keys in my Jeep commander this summer and was happy to have one to get into it as well...
you'd be surprised at how easy it is to use one of these to get into a car quickly. you can google the make and model and quickly find half a dozen youtube videos showing just the correct method...I keep one in all my vehicles.