Hello Sapto,
Thank you for the pictures. It looks great.
It seems from price are the Vanessa window bags and the Felleisen window bags kind of similar. Have I said that it seems that there is more storage space in the Vanessa window bag. But maybe that is the problem. If the small bag is filled up to the top, will it "bulge out" and so prevent the back seat sliding back? This won't happen with the Felleisen, because there is only one bag.
The Felleisen comes with a holder which can stay in the van. Maybe this is more reliable in the years to come. It would be nice to see both products side by side for better comparison.
Regards,
Eberhard