OK. Then it sounds like as you are loading models and/or skins that
have been visible at some point are 'piling up' in memory somewhere
and eating all your available space.

In that case, I would suggest using ent_purge and bmap_purge to flush them out.
As each model becomes "not visible any more' because your studio is viewing
a different car, then perform an ent_purge on the model that WAS visible.
This will flush the model from memory.
This MIGHT also flush its skins but Im not sure... It SHOULD at least flush the
skins embedded in the MDL file, at least I would EXPECT it to.

Then for any 'bodypaint' skins you have loaded to view on the model,
as soon as any one of these skins is no-longer visible, do a bmap_purge on it.

Following these steps sould keep your memory usage down.
The drawback of doing it this way is that EVERY time you change models or
bodypaint skins, the engine will need to reload that skin/model from disk.
If they are big, or a slow machine, this may cause a 'lag' as the file loads.

Also... doing a ent_purge or bmap_purge EVERY time a model or skin is changed
is probably rather overkill.
If you can figure out some form of counter system, you could probably get away
with only doing your purges when you have scrolled through 10 or so models/skins.
But this would take a bit of trial and error to find a healthy balance.


Best of luck all the same dude.