TOPIC:

My TL01 Subaru shell I recently purchased is quite battered, I would like to upgrade to a new shell but the only ones I can get hold of are transparent. How do I go about painting one? It seems very tedious and a long process...

You need to mask windows and paint it from inside with lexan paint. It is easy but need to be patient.

Have a look at this article:
tamiyabase.com/...ate-bodies

TBH the Lexan Brat shell is about as easy as they come:
- cut the arches, sills etc away from the excess
- wash the inside, no masking required if you just want it a single colour, window decals are the whole panel not just edges
- spray 2-3 coats on the inside (Tamiya PS-2 Red is closest to boxart IMO)
- peel outer & apply decals

... & you'll also need the taller rear body mounts (part # 0005349)

And if you will see how it's done I can highly recomend RCKicks on Youtube.
He is restoring vintage cars and have painted several of them on his channel.