Currently no manufacturers make laser grips for the 500.
I think that it would be nice to have them available. Crimson Trace has discussed the possibility of producing them if there is enough interest...in fact, the owner of CT has a 500 and would be behind the project.
If you would like to see laser grips for the 500 please go to...
Request New Laser Sight Models | Crimson Trace Laser Grips
...and make a request. It takes literally 30 seconds.
I was advised by Crimson Trace that this is something that they really look at...every vote counts.
Regards.