How powering PIC in auto ?

[Normnet]

05 = 5.6 VDC Working voltage

Try a few. They may reset the PIC because 5.6 volts is very close to
operating voltage of 5.0 volts.

It' s enough to use just one like in picture, or it's better to use one on every IO of PIC ?

I use one on every lead external to the board.

I would place the TVS in front of the volt reg to protect it also.

Norm