How can I find legitimate wholesalers (that is, wholesalers who
require a tax id to process an order) of after-market auto parts? I'm
not interested in those "scam" lists that you see all over the
internet.

Hello,

Good afternoon! After some searching I understand the difficulty you
encountered finding reputable vendors of aftermarket auto parts. Loads
of web sites with little or no information proving legitimacy. One
thing I tried was limiting my google search by domain. You can do this
by going to the advanced google search page (I'll include the url
below). On the advanced search page scroll to domain and enter "org".
Now you've eliminated tons of dot com sites. Below are two
organizations that I believe to be legitimate. They are associations
that seek to bring about better quality replacement parts through a
certification process. They also include information on their sites
explaining their mission and objectives. Both organizations contain
listings of member companies. Some of the member listings include urls
enabling you to go directly to their pages. I hope this is what you're
looking for. Please click on "clarify answer" if you are unclear about
any information provided here.

Certified Automotive Parts Association (CAPA)
Homepage:
<http://www.capacertified.com/home.htm>
Links to CAPA certified businesses
<http://www.capacertified.com/links.htm>

Automotive Body Parts Assoc.
Homepage:
<http://www.autobpa.com/>
-click on "members". There you'll find a roster of businesses arranged
by country and state.

Google search strategy
-I went to advanced search page
<://www.google.com/advanced_search?hl=en> and limited by domain to
"org".
-search keywords: 
---aftermarket auto wholesaler
---consumer aftermarket parts


Thanks,

rapidreference-ga

Thanks for your help on search strategies!