I have an 04 B6 and my taillights have always been different levels of brightness aka the left is much brighter than the right. At night it looks way tacky. My right brake light recently went out so i assumed that its dullness in the past months was due to the weaker dying bulb. I took it, it was changed and i asked the audi service guy about it and he said "The left taillight has one more bulb than the right". Can anyone vouch for that? Even if that is the case is there anything i can do to make my taillights appear the same dam brightness?

 

bad ground/earth problem mate a very common problem

 

So with that being said, is there any way to balance the lights? Is it true the left side has an additional bulb?

 

If the wattage of the bulbs is the same and they are from the same manufacturer, then they should be as bright as each other. Different filiaments, different gasses even differences in the filiament winding can cause different brightness levels.
Could be a bad earth, as proposed above, but also check how clean the reflectors and lenses are on the "dim" side. My old dodge looked uneven and I discivered that water was getting in an turning all kinds of colors.

Regarding two bulbs, some do have this, I know old european cars do (my 1989 Mercedes 300SEL had them). The second bulb was rated at something low like 3-5W and you turned them on (left or right independantly) when you were parallel parked on narrow streets. The MB was wide so these gave ongoming drivers a target (always avoided as that rear corner of the MB was solid).