Should you be arrested for some reason, it is best that you contact the 24-Hour Foreigner Service Hotline (0922-958-110) or a bilingual friend immediately. Although the police will do their best to bring a translator in immediately, it never hurts to have someone else around to help.

In serious cases it is strongly suggested that you contact your embassy or local representative office.  Since those offices are located in Taipei, they may refer you to the local warden for your nationality.  It is recommended that you register with your government office when you arrive in Taiwan and get the contact name and number for the warden of your nationality.

Useful Links:
Taichung Legal Affairs Office (in English)
Laws & Regulations Database of the Republic of China (in English)