My son is outfitting his 2008 Z and he's on a major budget. We are considering new Dual HU form Walmart or picking up an Alpine or similar used on eBay. The question is are we really going to hear the difference between the units? Looking at spending < than $200 on the HU. I guess other considerations are pre-amp voltage as he will eventually be adding an external amp.

For now he's just replaced the rear speakers with kickers and leaving the Bose I the door. Don't yet know what to do there.

 

First, I would highly recommend purchasing audio equipment from a more reputable retailer that offers a better returns policy and technical support. I've been using Crutchfield.com for years. They have an amazing selection to choose from, excellent lifetime technical support, fair prices, fast shipping, and they even match component selection based on your vehicle make/model. They also include detailed instructions for the install when you purchase from them.

In short, I cannot recommend them enough. They have live technical sales representatives, so if you want to know what your options are based on budget and goals, one of their associates can assist you (either live IM chat or via phone).

I'm a fan of Pioneer and Alpine, but I recently purchased a Kenwood Double Din with Wireless Carplay (DMX908S) and Focal Auditor speakers. My Z doesn't have the OEM Bose system and I'm not running a discrete/external amplifier. I'm still in the process of installing the Focal speakers, but initial testing so far proves they are far superior to the OEM Non-Bose speakers (made by Clarion).
Cheers!
-Icer