Custom Made 6x9 to 6.5" Speaker Adapters (Fits Dodge, Chrysler and Man – Sounds Good Stereo Online
Amazon.com: XtremeAmazing Car Stereo Door Speaker Adapter Mounting Plates 6.5 Inch 6.75 Inch 165mm Stand Ring Kit with Wiring Harness Cable Set of 4 : Electronics
2pcs 6.5" Car Audio Stereo Speaker Adapter Mount Black Spacer Rings Bracket Holder For Toyota Nissan Universal Solid Horn Pad - Speaker Mounts - AliExpress
How to Make Speaker Adapter Brackets - ABS Plastic - CarAudioFabrication - YouTube
Honda Speaker Adapter Kit and harness - Walmart.com