The E12 front anti roll bar bushes are known for squeaking. Mine have been doing it for the 6 years that I've owned it.
Always on speed bumps, although mine only kick off during the winter months (below 16°c) which I put down to contraction of the rubber. On the plus side it's never failed it's MOT, but it is annoying.
I've read that some owners have replaced the bushes to fix the issue and allegedly the new one's are an improved specification (if they're genuine Nissan parts)
I've never had a squeak from the rear of the car.

 

I'm not 100% sure it is front and rear. I wasn't paying full attention so I'll have to listen carefully. It might've been a case of thinking it was the rear when it was actually the front touching down after leaving the speed bump. Time will tell but I have a good idea what to check now thanks to you and tango. Thank you

Edit: Small edit to confirm it is only the front squeaking. There's a place I go where the speed bumps are generous enough that I was able to tell 100% it's only the front.

 

Try a blob of grease down there, that did it for me

 

I tried spraying some silicon grease into the bushes but access is difficult with the sub frame in the way and it didn't work on mine tbh

 

Re squeak: My bet is also the anti-roll bar bushings. They are cheap to buy, so won't break the bank.

Re door handle: You are unlikely to find them anywhere because I don't see them listed in the parts manual, unless you replace the entire thing. You might find reasonable success by sanding them down and repainting them with dashboard or plastic paint.

 

I have no way to jack the car up to check but I'm sure I can get a local garage to check. Found one that seems to be decent and won't rip people off which is the best you can get really.

I asked elsewhere and have searched for the door trim myself. It'll probably not surprise you that buying the entire door from a breaker is cheaper than just the trim itself. I'll likely do what you and others have suggested - mask it off, sand it down and paint it.

 

A small moan, the pic is poor quality on my phone.

However, I does look like everyday interior plastic.

Easy to mask off and refresh with a spray of paint after filling on the nicks on plastic.

I used to ride motorbikes.

Lots of faded plastics in bike world.

Only thing I found that worked long term
was vinyl spray paint from Halfords, etc.

Used on the big Suzuki & a Piaggio scooter dashboard.

Super surprised how well and durable it
was , considering the continuous outdoor existence, and no residue coming off it once dried.

Might be worth checking out

 

A small moan, the pic is poor quality on my phone.

However, I does look like everyday interior plastic.

Easy to mask off and refresh with a spray of paint after filling on the nicks on plastic.

I used to ride motorbikes.

Lots of faded plastics in bike world.

Only thing I found that worked long term
was vinyl spray paint from Halfords, etc.

Used on the big Suzuki & a Piaggio scooter dashboard.

Super surprised how well and durable it
was , considering the continuous outdoor existence, and no residue coming off it once dried.

Might be worth checking out

The photo was poor quality. I kept forgetting to take one when I was in the car and suddenly remembered while I was out yesterday. The sun was not in a cooperative mood!

I think I got into the mindset of just replacing it because it looks so insignificant and small. Then I saw that someone was trying to sell one for a ridiculous price. I think given your advice and other's advice I'll either try filling the nicks and painting or filling and just putting a wrap over it.

Thanks for the suggestion on Halfords spray. I seem to be spending more in there than I thought so it might be time for that premium membership lol

 

I had the roll bar bushes changed after 10 years but they normally stop squeaking when it’s wet out. But… when they went they squeaked more often, so sounds about right.