How about a HEPA filter in my '87 R30?

My '87 R30 sits for weeks at a time without being driven. After that long in the dusty southwest when I turn on the ac or just the fan I get blasted with dust and pollen. Aside from covering up the fresh air intake grills outside with some magnetic sign fabric I was contemplating somehow installing a HEPA filter - somewhere that would be "relatively" easy to replace every now and then. It would just plain be nice to have an active filter all the time when driving.

The obvious choice is between the blower motor and firewall. My concern is that it would greatly restrict flow in that position since it's such a small area. We already know that isn't the most powerful motor... it's adequate at best.

I wouldn't have a problem "ghetto modding" an existing filter to fit. But where?

I was thinking someone really clever already came up with a solution - but no joy after doing a quick search. Maybe I missed something? (and searching for "air filter" isn't an option...)

Thanks!

They do not sell one for square bodies, but might be worth reaching out to them- http://www.cabfreshfiltercompany.com/

I’ve got one I’ll be installing on my Dodge.