Additional alrme LED (J139)

I have just fitted a pedal lock to my 110 and to highlight the fact I want to add an LED just above it so anyone looking in can't miss it. The best way to do this is to run it off the stock alarm/immobiliser LED. I assumed it would be a flashing LED, but as it can flash at different rates is it a constant LED that gets pulses fed to it from something like a relay?

Also, what size LED would be best and should I run it in parallel or in series with the other LED - it's been a while since I have played with electrics.

Thanks in advance.