Hi David
As part of an extensive mod excercise on my A2, I fitted the bulb monitoring circuit to my DIS.
I can tell you that it's not a walk in the park - there is extensive wiring to be done - it's certainly do-able but it's alot of work. The wiring diagram is deceptive - black lines on paper are easy - adding wiring is another matter.
For info;
The monitor system basically "intercepts" the circuits to the; front main beams, rear tail lights, rear brake lights. It's fitted in series and reports a malfunction, be it wiring, fuse or bulb. To fit you would have to divert the existing wiring into the new relay housing and then extend to the circuits being monitored. The brake circuits will need additional wiring - on non-DIS vehicles, all three bulbs are on a single feed. Additionally, you must also connect two circuits to the instrument cluster for the display.
So, is it worth it?
If you want a "full house" DIS regardless, then yes. Given what I know now, would I do it again - yes.
I cannot remember when last I had a bulb out, so from that angle - def not a good idea.
Make your own mind up but if you proceed may I suggest you get some colour coded wires - it's so much easier.
blue skies
tony