
This Metra 40-GM21 adapter lets you connect an aftermarket antenna to your compatible 1998-2008 GM vehicle's factory-installed radio. Copper, polypropylene and steel materials and copper shielding provide durability.
Q: What is this product made of?
A: This adapter is made of copper, polypropylene, and steel materials for durability.
Q: How does the copper shielding help this product?
A: The copper shielding promotes optimal performance.
Q: How many adapters are included in the package?
A: This product comes with one adapter.
Q: Does this antenna adapter work with other car brands?
A: Yes, it is compatible with select 1985-2013 Chevrolet, GMC, Hyundai, Kia, Buick, Cadillac, and Pontiac vehicles.
Q: What does this antenna adapter do?
A: This Metra adapter allows you to connect an aftermarket antenna to your compatible 1998-2008 GM vehicle's factory-installed radio.
A: Take your car to the Geek Squad at best buy the tell you the exact one that will fit your car, that's what they did for me.
Customers enjoy this antenna adapter, citing its compatibility with various GM vehicles and its ease of installation. Positive feedback highlights its ability to improve Bluetooth and satellite radio functionality, while also praising its excellent fit and reasonable price. Many reviewers found it essential for completing audio installations. The adapter receives high marks for its performance and value.
The vast majority of our reviews come from verified purchases. Reviews from customers may include My Best Buy members, employees, and Tech Insider Network members (as tagged). Select reviewers may receive discounted products, promotional considerations or entries into drawings for honest, helpful reviews.

This Metra 40-GM21 adapter lets you connect an aftermarket antenna to your compatible 1998-2008 GM vehicle's factory-installed radio. Copper, polypropylene and steel materials and copper shielding provide durability.

This adapter allows you to adapt an aftermarket antenna to your OEM radio in select 1988 - 2006 GM vehicles.

Eliminate the need for an aftermarket Satellite Radio antenna with this Maestro HRN-ANT-SAT1 adapter, which allows you to use your factory satellite antenna with an aftermarket Satellite Radio. The SMB connector enables versatile use.
| Pros for Metra - Antenna Adapter for Select 1985-2013 Chevrolet GMC Hyundai Kia Buick Cadillac Pontiac - Black | |||
|---|---|---|---|
| Compatibility, Fit, Installation, Antenna Adapter, Price | Installation, Compatibility, Ease of use, Fit, Reception | Compatibility, Installation, Fit, Performance, Radio | Compatibility, Installation, Performance, Ease of use, Antenna |
| Cons for Metra - Antenna Adapter for Select 1985-2013 Chevrolet GMC Hyundai Kia Buick Cadillac Pontiac - Black | |||
| There were no cons for this product— | Static, Signal | There were no cons for this product— | Price |