In 2014 I put an Eonon GM5150 into my E46 with factory Nav and connected a backup camera as well. There were a few initial software glitches but the tech rep on the E46 fanatics forum responded quickly with firmware updates and I am a happy camper with the unit for the price I paid.
I rarely listen to the FM radio side of the unit but when I do the reception is fine. The METRA 40-EU55 antenna adapter is what I used per an E46Fanatics.com DIY. Many people using the Eonon supplied adapter reported problems.
Here is my installed unit:
https://youtu.be/gKfVR90aIRY
PS: I changed my factory fuse in the fuse box to a 15 amp from the OE 5 amp to match up with the fuse size of the Eonon head unit.
My E53 Factory Nav screen is still doing well so I have been holding off on replacing it with the D5166XU for $275. I'll buy it via PayPal and if I have any problems I'll return it.
Eonon 7" Car DVD Player Monitor GPS BT Digital O BMW E53 Touch Map DAB+ DVB-T | eBay
Mike