This is not normal, I too have a similar problem, but on a 2007 Honda Civic coupe.
The halo effect is caused by tint material and rear defroster line contact.
From reading other threads (do a search), ceramic tint may be a better alternative.
I haven't tinted my ES350 due to the potential 'halo' affect.
Once tint has been installed on the rear windshield, you risk damaging the defroster lines upon removal of the original tint.
My advice is to do your homework, ask around, and maybe view previous tine work done by installers.
I've had my Civic tinted for almost one year now and the 'halo' affect has not gone away, so if a tint installer is giving you that line - bull crap.
Good luck...