One problem related to tail light has been reported for the 2004 Toyota Prius. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Prius based on all problems reported for the 2004 Prius.
Tail lights on my '04 Prius are slowly melting , and as a result, the decorative black plastic inside the assembly is obscuring the brake lights to the point that they are barely visible. I will need to replace these soon; Toyota refuses to do it, saying I am out of warranty.