i would suggest you to my father n law, who owns a Diesel Performance/ General automotive shop in Midlothian with 30+yrs ASE experience with warranties...
but if you want dealership..
Go to HILEY MAZDA in Hurst or Arlington..i bought my M3 from HILEY in Arlington...they have some damn good top...
new member from DFW, Glenn Heights actually...kind of Desoto region...so where are all you guys located at? looking for some local people..meets in the southern region anywhere?(shocked)