Brads custom auto is amazing for performance upgrades. If you need any clear paint protection or paint coatings benchmark auto salon is also amazing. Good luck
Several shops in our area come to mind. As mentioned above, Brads Custom Auto in Seattle is great. Blood Enterprises in Auburn, TMS in Kent, Bowen Scarff Ford Lincoln in Kent, and Bickford Motors in Snohomish all come to mind, as well. The vast majority of modding on my Mustangs (from superchargers to rear end gears, exhaust, suspension, stall converters, etc.) was done at Bowen Scarff.