Fuck me I didn’t do anything on the btr just because I couldn’t be arsed to go and buy some CA glue for the lamps, oh well.
>>5835788I'll post some image refs so you can get some inspiration, although they were used mostly in winter. They look improvised but there must be some official pattern issued with the shape of the turret but I’m not quite sure, probably any fitting tarp would do the job.
There are several ways:
Paper tissue wetted with white glue and water
Lead foil
Green putty (I don’t remember the brand but there are several companies, I think its miliput or Tamiya bicomponent)
Also here's a link with a how-to tarps (so you get a base to work on):
http://www.militarymodelling.com/news/article/making-realistic-tarps/3310 