Help with stereo wiring

[burger]

Hi,
I've just bought a new head unit due to my last one blowing up in smoke and would like some help with the wiring.
The new head unit is a Pioneer SPH-DA97DAB and I'm using the Connects 2 harness CTSBM009.2AA.
Most of the wiring I know where to hook up but I'm having problems finding where to hook up the following :-
1)The reverse signal wire.
2)The car speed signal input wire.
3)The handbrake wire.
I guess there must be a wire to connect to 1 & 2 next to the head unit as the harness cable is only about 9cm long.
The handbrake wire, does this need to be connected to the handbrake switch or can it be connected directly to ground ?
I've been looking round the threads and I've started to confuse myself, so any help would be appreciated.
My car is a E88 2011.
Thanks again.
Lee