I modified the config to position the fuel truck beneath the left wing rather than beneath fuselage.  I don't know if its the proper location, but at least the truck doesn't look uncomfortably wedged beneath the airplane. 

Here is the file if you or anyone is interested.  Look for your current gsx.cfg file and change that to gsx.bak (incase you don't like this one), no need to remove it from the folder.

Then change the extension of this file from gsx.txt to gsx.cfg and place it in the same folder. 

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