For number plates, you don't need to change front and back in a pair. Unless you are very particular that both lettering must be the exact same one. Else, you can do only just one, depending on which one cracked. You can even just stick back a single letter if it fell off.
I'd say no more than RM30 depending on the size of the plate for JPJ compliant (cheap) ones. If you want some with fancy lettering, reflective lettering, semi transparent lettering, custom plate material (not the standard black ones) which btw are "considered" illegal in JPJ's view. Those would cost a bit more than normal ones. Up in the hundreds is not abnormal for those really fancy ones.
The problem is the entire system, not the HU alone. Once you change the HU, you will realize the speakers are rubbish as well.
No HU is plug and play as it is meant to fit universally on all cars meaning it is a wired in connection. If they were to make specific models for specific cars. Their inventory would be same as the wiring harness are not standardized on all car.
As long as the shop does not cut your original wiring harness to wire-in to the HU, it should be safe.
Most of them in fact will try to sell you this standardized adapters specific for your car which plugs into the original harness on one end and does not terminate with any connectors on the other so it can be wired into the HU without meddling around with factory wire harness.
If anything were to happen with electrical, at least you can put the original head unit back in and no one will know the better.
Even the speakers have specific harness adapters which you can find on taobao.
https://www.crutchfield.com/p_120701729/Met...ss.html?tp=2977If the engine has too much water going in, it would have killed itself as water is non compressible and if it enters the combustion chamber, it would cause damage beyond operation.
Also, unless you have drove through a flood. Unlikely the water can do much damage as the bottom end of the engine is usually quite water tight.
No need to buy a number plate from Honda. They don't make number plates. Even if they do for you, they get it from outside of their service centers.
The engine is a pretty hot place, any waters that can go into the engine would either cause damage almost immediately or would have evaporated quite rapidly.
It might be in your mind after all if you ask me.
SO... I can change the HU provided that the installer doesn't cut the cables. Leave the original cable and if something happens, I just switch back to the original HU.