www.opel.de Official Opel factory website from Russelsheim, German. Text language is German, and requires Macromedia Flash 7 program download for front page displays.
http://a.webring.com/hub?ring=opelring The "Opel Ring" features a random listing of Opel-related websites, some featuring personal information others featuring various Opel car models sold elsewhere than the North American market.
www.ebay.com A search of "Opel GT" "Opel Manta" "Opel Kadett" typically lists cars and parts for sale. (Note: Not all sellers are knowledgeable or accurate, so Please exercise caution in all purchases for Opel items).
www.opelgt.com The most active Opel resource in North America, it features a combination of sometimes folksy discussion with technical suggestions and parts advice. Some features require online registration for access.