contrary to what the Mets have been saying the last 2 years, parking is fine if you are early. parking is, however, a mess if you get there once the lot fills up (normally 40 minutes before game time you are still ok, but for mets-yankees i'd be earlier.) i've never tried to bring a backpack in, but my shopping bags filled with food have never received more than a cursory "open that for me...ok go on in" from the mets website: ]How early may we enter Shea Stadium prior to the start of the game? Gate C opens two and a half hours prior to the scheduled game time. You and your guests are invited to enter through Gate C and enjoy batting practice from your ticketed seats. All other gates open one and a half hours prior to the scheduled game time, except the Diamond Club entrance, which opens two hours prior to the scheduled start of night games. Opening times may vary for doubleheaders and special game dates.