Here is a video demonstration of how hot it can get in a parked car for a pet (and people!) in hot weather, even with the windows cracked. Too many pets die and suffer because of being left in a hot car, because of owners not being aware of how dangerously hot it does get in these cars
This is a very effective demonstration and will make you see how significantly elevated the temperature becomes and how deadly this situation is for any pet/person left inside these cars. It is imperative not to put them in this situation and please share this information with others so we can prevent any of these tragedies as during the summer heat (but it can also happen during hot days in other seasons as well).
This should open your eyes about dogs in a parked car, even with the windows open! http://www.ebaumsworld.com/video/watch/82689781#72uE57p8yLtQEDLZ.32