Unless Cadillac gets purchased by Toyota it is not an appropriate comparison. American parts assembly owned by Japanese Multinationals and you get: McIntosh (but they still call upon some of the best they have had to design some of their best tube stuff today, not all bad); Levinson (fire a much of staff, cheapen the build quality to a degree (sort of like Levinson lite), and move the factory) why: Call it Harman Internationalism. Well at least they still have an American presence.
My votes go to companies that have maintained cutting edge design teams, passionate audiophile firms, fanatical customer support, support their USA employees with real world benefits like hopefully you and me, example: Audio Research, Jeff Rowland, Wilson, Vandersteen, Krell Industries, Conrad Johnson etc. Some promising new comers include Talon Audio etc.
Map of Hi-end Audio ompanies in the USA that still manufacture in the USA to my knowledge, not necessarily any longer USA owned( list to grow whenever I get some free time) at:
http://www.fototime.com/0F4E679DC30CF7C/orig.jpg
Cheers!