Porsche Cayman License Plate Bulb Size

The Porsche Cayman license plate light uses a DE3423 bulb size for the exterior illumination component located at the rear of the vehicle. Data for the specified lighting equipment covers the period from 2006 through 2012.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Type	Shop
2006-2012	DE3423	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423	Check Price

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Additional Notes

The Porsche Cayman uses the DE3423 bulb for its license plate lighting across the 2006-2012 model years.
The DE3423 is a festoon-type bulb, meaning it is cylindrical in shape and makes electrical contact through metal caps at each end rather than through a base plug or pins.
Festoon bulbs are held in place by spring-loaded clips within the housing, with the end caps pressing against the contacts to complete the circuit.
The DE3423 has a specified length of 41mm, which is a critical fitment factor, as festoon bulbs must match the span between the housing contacts to seat correctly.
The bulb operates at 12 volts, consistent with the standard electrical systems found in passenger vehicles.
The DE3423 designation follows ANSI standards recognized in both the United States and Canada, indicating the bulb meets defined performance and dimensional requirements for those markets.
Because festoon bulbs are available in multiple lengths, such as 28mm, 31mm, 36mm, and 42mm variants, substituting a bulb of a different length than 41mm risks poor contact or failure to fit within the Cayman's license plate lamp housing.