Autoklub
Website of the Bohemia Assistance Breakdown service. In Czech only.
http://www.aba.cz/

International SOS
International SOS can arrange for mechanics, tow trucks, rental cars and emergency accommodation in the event of a breakdown.
http://www.internationalsos.com/countries/CzechRepublic/

UAMK
Emergency breakdown cover for motorists. The website also includes traffic reports.
http://www.uamk.cz/index-e.htm