Here's what you need to do, to get both parking lights to flash. You'll need two relays, standard 5 pole.

Relay # 1:

* 87 & 85 : Light Output from alarm/RS unit
* 86 : Ground
* 30 : To left side of parking lights (terminal 58L)
* 87a: NOT USED

Relay # 2 :

* 87 & 85 : Light Output from alarm/RS unit
* 86 : Ground
* 30 : To right side of parking lights (terminal 58R)
* 87a: NOT USED