I want to say something positive about Phoenix Raceway. As someone that has also went thru the same issues, I am very empathetic to people needing ADA parking that did not receive it....I need to point out a few things. First of all, Phoenix Raceway provides more than the legal requirement of spaces. They recommend on their website to arrive early in order to actually get a spot. If anyone would have called, they would have recommended that in order to guarantee parking in unreserved ADA you'll need to arrive right when the gates open. That extra bit of research could have prevented some of the problems seen.
Secondly, if someone is resigned to a wheelchair, on oxygen, unable to take stairs ECT, I would assume you would have purchased ADA seating. Included with ADA seating is a reserved ADA space. They do this to make sure that the people that need it most, that have committed to the mobility impaired seating, have a guaranteed place to park close to the gates. They also provide a free shuttle service from the reserved and unreserved ADA lots that take you straight to where you need to be.
No event will ever be perfect but at the same time, I feel Phoenix Raceway has went above and beyond to try to make this event as inclusive as possible.