VW had 6v and 6v/12v-selectable radios with AM, AM/FM (and some with Marine Band, ShortWave, or LongWave - at least 5 combinations of bands). The Beetles had the cheapeast radios (Sapphire ?), while the Type III models (Squareback Fastback Notchback) and maybe Ghias often had better radios.

Here is one on eBay (although the listing information is weak): http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6763&item=7905901577

Tim