Random dash lights flashed up!

[rllmuk]

I was driving to the airport last week when on the way some of the dash lights flickered up for a split second, too quick to notice which ones, and went off again. Forgot about it and went on me hols.
Then, on the way back from the airport a couple of days ago the same thing happened, different combination of dash lights, but with a jolt through the entire car as if it stalled, only it didn't (I was doing 70mph at the time). Once again the lights were visible for all of half a second.

I've ran a vag-com error check on it, which was clear, and the battery voltage is as it should be (only thing I could think may cause it).

I had a sub installed about a month ago which has a feed off the battery, but surely that couldn't be causing it? A search has not been helpful either, anyone have any ideas?

 

[skahigh]

perhaps if the sub made a sudden draw on the battery the voltage to the ecu would drop and cause it have a spazz but not actually generate any fault codes?

 

[skahigh]

i had a problem like that when my alternator went on the fritz in my focus. got misfires, engine management lights and all sorts but no fault codes!!!