Amazon.com: ASC 6+-Inch 6" 6.5" 6.75" or 6x9 Front Car Speaker Install Adapter and Tweeter Mount Bracket Plates w/Speaker Wire Connectors for Select GM GMC Vehicles- See Below for Compatible Vehicles :
Universal 6x9 5x7 6x8 to 5.25 6.5 Inch Car Speaker Adapter Brackets Pair - Walmart.com
Amazon.com: Metra 82-3004 2014 6X9" Speaker Adapter for Select GM Trucks,Black : Electronics
LEEWA 1set Car Stereo Speaker Spacer Mat for Toyota Camry & Tacoma Change 6x9" to 6.5" Front Speaker Adapter Spacer Ring Pads|Cables, Adapters & Sockets| - AliExpress
For Toyota 2002 2011 Camry & 2005 2015 Tacoma change 6x9" to 6.5" Front Speaker Adapter Spacer Ring|6.5 speaker adapter rings|6.5 speaker adapterchanging ring - AliExpress
Leewa 10pcs 6x9 To 6.5" Car Speaker Spacer Solid For Subaru Forester Front Door Audio Pad Mat Adapter Modified Rings Kit #ca5523 - Cables, Adapters & Sockets - AliExpress
4pcs 6x9 to 5x7 or 6x8 Car Speaker Adaptor Ford Chrysler Dodge Mercury Plymouth | eBay
Metra 82-5602 6X9" Speaker Adapter for Ford Explorer 2011-Up - Warehousesoverstock
Speaker Adapter for 1993-1996 Mazda MX6 5x7 6x8 6x9 to 6.5