Wiring Remote Keyless Entry - Help with with right wiring

Been reading through a fair amount on the site and haven't found what im looking for, hoping some of you will be able to help me out here...

I've got a Celica Gen7 2002 (UK).

It had central locking already but i wanted a remote entry system so I bought a system off eBay.

I managed to locate the power unlock and lock by following the correct wires from the central locking button inside the car.

Now I need to know where the left and right indicator wires are, So I can attach the relevant wire from the remote system, to flash the lights on open and close. How would I find these?

Also, after all this, I found a 'spare key' which actually has a remote locking system with flashing indicator lights n all. I don't want to use it now however, so finding the correct wire to the indicators to connect to my new system is the next step...

Any help will be greatly appreciated!

I have basic tools, and a DMM to help find wires etc.

Thanks in advance!!!