I upgraded my Z4 E86 with the components below. Enjoy.
Alpine iLX-W670
https://www.crutchfield.com/p_500ILXW670/Alpine-iLX-W670.html
JBL DSP4086
https://www.crutchfield.com/p_109DSP4086/JBL-DSP4086.html
Metra 40-EU10 Antenna Adapter
https://www.crutchfield.com/p_12040EU10/Metra-40-EU10-Antenna-Adapter.html
Metra 70-9003 Receiver Wiring Harness
https://www.crutchfield.com/p_120709003/Metra-70-9003-Receiver-Wiring-Harness.html
Crutchfield CK8 Amp Wiring Kit
https://www.crutchfield.com/p_007CK8/Crutchfield-CK8-Amp-Wiring-Kit.html
Amazon Basics 2 RCA Audio Cable
https://www.amazon.com/dp/B01D5H8PQ0?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
