editing truck_dealer .sii files with addon_hookups?

hey guys,
i have a small problem; i created a hybrid truck (old Actros with new Actros interior), yet as soon as i want to customize it, the interior reverts to the standard Trust Edition one.
my workaround would be to add in the additional lights/horns on r_grill, b_grill etc. via the truck dealer .sii file,
but i can't figure out how.
anyone got an idea?

Are you adding in new .sii files?

You can only edit dealer files, if you want it to work with MP.

The Leeds Lad wrote:Are you adding in new .sii files?

You can only edit dealer files, if you want it to work with MP.

yea i know, i'm editing the standard files (like you do), but i want to add lights etc. to roof mounts because i want a truck with another interior, but as soon as you enter customization ingame, it reverts back to the non-edited interior.
so basically i want to buy the ready customized truck directly at the dealer

You have to add the customisations either in the dealer file or your save file. However most trucks with a Renault cab seem to be immune to the reverts and crashes.