The Classic "Air Wedge" from HPC (AW99) -- Reliable, Durable
This is one of the best tools of its type that I have ever had the occasion to use, and I use this model often because it has proven to be well made and tough as nails. These 'air wedge' tools are prone to leak or simply come apart, but the AW99 seems better made than some other brands on the market.
Use the Air Wedge instead of hard wedges to safely pry the window glass of a vehicle away from the door sill, to give yourself more room through which to insert your car opening tools.
In addition, it is exceptional when used to pry a vehicle door at the top or rear edge, creating a space through which to introduce 'through the car' opening tools. In some cases it pays to have two wedges with a space between them for your tools.
I've used the AW99 in more situations than I can recall.