In February of 2002, Winnebago successfully secured the permission of Volkswagen to allow for a modification to the sheet metal belly-pan which would provide direct access to the oil filter without removal of the belly-pan.  The modification can be performed without any loss of warranty status from Volkswagen.  The modification consists of nothing more than a small cut out in the pan directly below the filter area.

There still are those that don't wish to perform the modification because they prefer to remove the belly-pan each time the oil filter is removed.  The reason is that by removing the pan, a complete visual inspection can be performed of the engine area.  This can pinpoint oil, fuel, and coolant leaks as well as expose any loose or vibrating parts that need to be re-tightened.

This service bulletin from Winnebago provides a full size template for making the cutout in the right position along with instructions and photographs.  The only tools need are tin snips, metal nippers, or a metal saw such as a jig-saw with a thin sheet metal cutting blade.  Once the cutout is performed, the rough metal edges need to be filed or sanded down to remove all of the sharp edges.  Winnebago recommends the installation of a rubber edge trim to cover the exposed rough edges but it is not absolutely critical, especially if you make sure that all of the sharp points have been removed.

NOTE- I've been told that the template layout for the cutout is slightly out of position in relation to the actual oil filter.  Before you actually cut any sheet metal, verify that the location is centered on the oil filter.

 Winnebago's Service Bulletin #7SB001-02-01A  (PDF)

Additional Modifications: