See photos where i have added 2 sections ineternal roof to seal off the open area front of pop top bed. Suede lining bought , slight diffrent colour to van convertors ... mdf with 1 section hinged to allow full access to bed area when roof up .. the front section fixed via hidden plates inside and swivel clip to front to stop it dropping. Roof can be closed down from the smaller front section ... but may need some different clips to final version but it can be done relatively easy. Sort of Cali style to close off bed area to van when not in use.