I live in Europe and what we (me n some buddies) do is the following: we got ourselves an old wheelchair from the salvation army, we took out the seating and replaced it with minimal padding and 3 winebags (camelback-like bags that cost nothing but are virtually indestructible) and we fill em up with booze and stuff em in the seating. Then one of us plays crippled, since it aint easy to frisk handicapped people he can carry lots of stuff on his body as well.
Then they let us in and depending on how big the concert is we get acces to a special wheelchair podium where you have like VIP spots for every concert. and if we wanna feel the festival, we take wheelchair rolls, one of us stays in the chair and the others go party if they want and then every hour or so we switch. Or if the concert aint worth anything we just take out the winebags and 2 of us roll the wheelchair to the camping and hide it in the tent or in our car if its just 1day...