Does anyone know how to take screen dumps from a nav computer?..

Basically Im looking to skin roadrunner for my carputer so it replicates the look of the nav system, but rather than starting from scratch was wondering if its possible to just dump out screens somehow, or extract them so I have the correct files to start from?..

Im guessing its not as simple as using something like gif extractor and hunting through an iso of the OS, but if anyone has any pointers Id be grateful.. in particular Im looking for the Aux (audio) screen and the main menu

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