We are experts in this field
To retain the function of your factory antenna you may well require an antenna adaptor. They connect behind the original radio and alter the plug from the manufacturer specific version to an industry standard, usually male ISO, ready to plug in to your aftermarket stereo.
Antenna adaptors vary depending on the manufacturer, model and year of your vehicle. We would always suggest using our registration lookup or what fits my car tool to display to you only the variants suitable for your vehicle.