"Mule testing with some modifications to the current Quattroporte The Maserati Quattroporte is getting a little old and may be due for a new iteration or an all-new replacement.

Here our spy photographers have caught a Quattroporte mule prototype testing with possibly a new engine. In these photos we can see small mounting covers in each of the four corners of the bonnet, which suggests the bonnet which is non-standard is bolted in as opposed to having hinges.

The purpose of this could be either to make room for testing equipment or a new engine which requires more top end space. Also seen is a modified rear bumper and new rear exhaust. Our spy-shot sources also report that the next Quattroporte or its replacement will be slightly smaller than the current model."

Maserati Quattroporte mule spied testing new engine - Photos