Hi mate - quick response as I'm literally finishing up my install right now.
1 - the plastic shroud just slides off - though this may be dependent on the version of the unit you have:
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I purchased mine a month ago so should be the latest 8.8". You can see the 2 black lines I've marked on the shroud where you need to trim
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just did a test fit and its perfect now. I can raise it up another notch if I want
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Next project will be to paint the shroud and clean up the cutout, and paint the backside of the screen black as others have done, and bend the tabs on the joying to push it even further in, though it's pretty flush as it sits.
2) had the same thought as you about the bundles of wires. Fortunately the 4C has lots of space so I tidied up all the cabling and tucked it in neatly without hacking the unit, in case I ever want to sell it in the future. For a surefire answer - reach out direct to Joying support, they're good at replying and will be best to answer you question
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