The concept of using low power microwave energy to efficiently assist the regeneration of ceramic monolith diesel particulate traps is explained. A prototype Microwave Assisted Regeneration (M.A.R.) system is presented and is demonstrated to work reasonably well on both bench and engine tests. The system, which is inexpensive, reliable and controllable, requires 1 kW of overall electrical power for a short period prior to trap regeneration.The M.A.R. technique presented merits further consideration as an alternative to other proposed vehicle trap regeneration systems.