Can elaborate what do you mean by "adjusting sidemirror angle switch" ?

For trunk release, do you mean add a button between rear tail light, press that button to open trunk?

Change side mirror switch is easy, but by changing switch alone wont get the function of folding side mirror.

To have electrical folding side mirror, following mod requires:

Material:
- Preve 7 wires side mirror 1 pair
- 2nd hand side mirror relay & side mirror switch (probably mitsu evo one)
Work:
- attach Preve side onto your existing saga vvt side mirror's tapak (bottom 3 screw position is the same for both model)
- wiring mod to test n connect all wires & relay & switch (switch may even come with led lights)
- modify the tapak until its raise up enough to have sufficient clerance to fully fold back (if dont raise up a bit will only fold half way), and therefore screw at bottom cannot be fully tighten.
- switch over the painted side mirror cover from ori saga (assume its painted) to Preve side mirror (assume Preve one is non-painted)
To add a button to unlock trunk (much easier but not many shop know how to mod)
I'll share some pic later when i have time.

if you want to get it alone, can try this (i saw it in fb, nvr try his service though, also not sure how his button look like)



and, if have to use remote to unlock first (for car w/o keyless entry), may as well just use remote to pop the trunk (for new saga).

also not sure why this guy only state for blm/flx in 2018, where saga vvt ady launched since 2016.

Normally signal flash 5 times is attempt to arm with remote, whilst one of the door/front/rear bonnet not close.

But, your case is unable to unlock with 5 times signal blinks.
If really checked and all doors/bonnet closed ady, and meter panel does not indicate any door/bonnet open (2019/2020 new Saga),

Try change remote battery
Try with your spare remote (hopefully battery still strong)

If after unlock manually (alarm goes off), press disarm, alarm quiet down, then try close all door and arm again.

If by then still unable to arm with 5 flashes, then try disconnect your battery terminal, leave it > 10 minutes, reconnect and try.

If still cannot, then probably one of the sensor / meter IC board got issue ady, which will be difficult for SC to troubleshoot...

I hope yours is just a weak remote battery thats all. Happy CNY!

Did this happen after a car wash? If yes it should work once the sensors are dry again.

Dont force close your bonnet too hard ya