Are you referring to the standard radio antenna on the passenger quarter? We've been discussing swapping out the xm/OnStar antenna on the trunk.I bought my stubby antenna from Dave at PAW 🐾...... it’s about 4” and the price was around $20.00. The reception has been great, even on the highway.
I drove to his shop and he even let me try it before paying for it. More than fair!
Interesting thought.Looks like there held together with torx screws. Could you possibly open them up and transfer over the OEM‘s internals to the new one?