$2k for HUD would be worth it if it can be read with polarized sun glasses at least. BMW would never bring the HUD to the 3 unless competition forced it to, they don't want to lose 7 series customers.
Speakers: CDT Audio HD-42 comps--front doors (RAAMmat deadened), CDT ES-06 6.5" woofers--kickpanl Pods, Hertz EBX202R dual 8" ported trunk sub. Amps: Phoenix Gold RSd 500.4 (comps & pods). PG RSd 600.1 (sub). Power & Ground: 4AWG Streetwires w/RockFosgt RFDB1 distro blocks. Input: HU lineout--Kicker KISL RCA adapters--RockFosgt RFIT-6 cables--Audiocontrol Matrix--Monster cables--RSd 500.4--lineout Monstr Cabl to RSd 600.1.