RC Car Parts / Carbon? / The right printer???

[curious aardvark]

well, there are a number of better options.
printers with larger build volumes, idex print heads and an enclosed print volume.

You seem to be going about this the long and difficult way round.
Prusa are okay, but the 3s is still using really old motherboards and printed parts.

have a look at: https://www.amazon.com/FlashForge-In...1909811&sr=8-3
That's the cheap option and you'd need to upgrade to hi-temp 300c hotends for polycarbonate.
Not the largest build volume - but for rc car parts - should be plenty big enough.
Flashforge used to offer a hi-temp option on the extruders, so might be worth

for a larger print volume and hi-temp single exrtruder: https://www.amazon.com/Flashforge-Gu...%2C729&sr=8-15

But the one I would be looking at if i were you is the creator 3: https://flashforge-usa.com/collectio...ed-refurbished

If I were buying an i3 printer and building an enclosure, I would go for the tenlog Tl-D3 Pro
https://www.amazon.com/TENLOG-Indepe...47&sr=8-3&th=1

better electronics than the prusa, also linear rails which prusa don't have on their i3's, 300c hotends, idex printheads for using soluble supports on awkward shape prints.
Just better hardware all round and less cost.

When buying an I3 - buy the hardware NOT necessarily the brand.
The prusa machines are decent, but massively overpriced for what you actually get.

Think of it like buying a mobile phone.
You can buy an off-brand android phone for 50% the price of a samsung, it'll look better, have better specs and hardware.
It just won't have a designer label.

How much are you prepared to pay for the 'label' ?

So there's a few more options to look at and think about

here's another one to consider: https://www.amazon.com/QIDI-TECHNOLO...%2C555&sr=8-31

Although - personally - I'd avoid a dual extruder and go for an idex instead.
With both printheads on the same carriage. you end up having to print a lot of ooze towers and shields.
But if you were only going to use the dual extrusion on the odd occasion, would be fine.
It's a decent looking machine. And will automatically adjust the height of the nozzle not being used, so it doesn't catch on the print.
Not quite as good as an idex - but better than a standard dual extruder.
(finds price) it is kinda pricey though.