The MGP web site I located to include in with the San Antonio location listed the San Antonio location (Malibu Castle) as the only MGP still in operation in Texas.
I actually thought there were more left. Just nort of Austin in Pflugerville is a massive family play, race and mini golf place. But that went in after these images were captured.
Anonymous
@ 2009-09-06 02:30:00
Isn't this the place where in 1983 two fired employees murdered four employees?
From Wikipedia.org
This location was the site of the infamous Malibu Grand Prix murders. The murders were committed on July 1, 1983, during the course of a robbery and resulted in the violent deaths of four employees who had recently closed the store and were in the process of conducting post closing housekeeping duties.
Anonymous
@ 2011-04-05 22:11:57
There's a KIA dealership on the site, and if you check some of the online maps, you (perhaps used to be able to) see some of the track lining and asphault.
Raceways - Misc, Abandoned 
From Wikipedia.org
This location was the site of the infamous Malibu Grand Prix murders. The murders were committed on July 1, 1983, during the course of a robbery and resulted in the violent deaths of four employees who had recently closed the store and were in the process of conducting post closing housekeeping duties.