Risk is a very subjective call.
The fault, from what I remember, is that the rear loom might stop working.
I would worry that you may not become aware of it when it does stop working if it does stop. Then because you have no rear lights and are forced to break heavily one day in trafic you end up being rear ended. If I was the driver behind you the fact that you had no lights would piss me off, and I could imagine this would start causing all sorts of insurance grief. Particulary since you chose to ignore the recall.
I might be a bit of a nervous nelly, but if it were me I'd get it done. I'd also accept having to get the extra audio gear out of the way is my problem, as it's not the dealers fault you chose to put the extra stuff in the boot.
Just my opinion.
Paul