Orlando Sentinel article with more information: http://www.orlandosentinel.com/news/breaking-news/os-richard-petty-fatality-20150412-story.html
Richard Petty Driving Experience is the operator/vendor: http://www.exoticdriving.com/about/
Looks like the track is scheduled to be closed in August of this year (Disney is going to build something else there?): https://en.wikipedia.org/wiki/Walt_Disney_World_Speedway
The OS article states that the deceased passenger was an employee of Petty Driving Experience, and the driver was the customer (24 y/o).
Parking. With the recent expansion to the Magic Kingdom Park, they need the space to park more cars since they increased park capacity by 5-10k people per day (on average). The Speedway was a failed idea in the first place, and letting the Richard Petty folk operate there was a way to recover some of the lost costs, but now they actually need the space.