Auto Unlock Relay

I want to add auto unlock to my car which has positive Door Locks.

I have looked at the Door locks section of the 12Volt install bay.

Do i connect it up according to the 'Constant to Momentary Output' relay diagram?

i.e. Relay Pin: 86 - Switched 12V+

              Pin: 87 -  Fused 12V+

              Pin: 85 - Ground via a 1K uf capacitor & a 10K fixed resistor

              Pin 30 - momentary 12V(+) to door Unlock wire

The Diagram in the Install bay also shows a connection between pins 86 & 85 with a diode pointing towards pin 86

Why Do I need to make this connection?

Also should I not add a diode on the switched 12V(+) wire with the diode pionting towards pin 86,  hence preventing 12volts from flowing back?

Any help appreciated 

regards.

Sungura