There are other things to consider besides looks, though. First, let's clear up some terminology that people mis-use:
- The lights that are located in the bumper, facing sideways, near the extreme front of the vehicle, are sidemarkers. They aren't 'bumper sidemarkers', nor in most cases 'parking lights'; they are sidemarkers.
- They must be visible to the sides of the vehicle, located as near the front as practical, and within a specified height range.
- They must illuminate amber. There is no requirement that they have an amber lens, but...
- There must also be an amber passive reflector located on the side near the extreme front of the vehicle, with similar height requirements as the sidemarkers. The common way this is accomplished is to make the sidemarker lens a passive amber reflector, so both requirements are covered with one part.
Audi did a sneaky (and stupid) thing for the North American market A3. Since the sidemarkers on the A3 are located in the curve of the bumper so they are visible from the front as well as from the side, Audi decided to use them as the front parking lights also (claiming that the one lamp meets both regulations and serves both purposes). I mean, come on.... all A3s in Europe have City Lights, why not just do the same for the North American ones?
Some people incorrectly refer to the turn signals on the fender as 'sidemarkers'. They ARE NOT sidemarkers! They are properly called 'repeater turn signals', since they mimic or 'repeat' the turn signals on the front and rear. They are required in Europe and most of the rest of the world, where the regulation is roughly that a turn signal must be visible when you are at the rear of the vehicle and 1 metre to the side. In that position, you can't see either the front or rear of the car, so a turn signal has to be placed somewhere so that you can actually see it. This is usually on the front fender, above or behind the wheel well, but may be on a mirror or anywhere else that it accomplishes what it needs to do. These types of turn signals are permitted but not required in the US. They are not to be illuminated with the parking lights, only as turn signals. Personally, I insist that they must be present on any car I own.
The ECS sidemarkers are in fact passive reflectors, but white ones. They do illuminate amber since they have an amber bulb. So, the 'amberness' of the passive reflector is the only part of them that does not comply with FMVSS 108. Since the passive white reflector is actually brighter than the original amber one, I don't believe any safety or function is compromised by this cosmetic improvement, and I don't think that they'll attract any enforcement/inspection attention (FMVSS 108 only applies to new cars made for sale in or imported for sale into the US. States may base their own regulations, inspection and enforcement on it, but strictly speaking, the Federal regulations have no effect on the owner of a vehicle. I Am Not A Lawyer, and This Is Not Legal Advice, just my understanding of it.) In any case, they're so easy to change that I could swap back to the amber lenses in a matter of minutes.
For the left one, open the hood and reach DOWN below the headlamp until you can feel the sidemarker from the back side. release the clip and push it out from the frontmost end. Unplug the bulb from the original one, change the bulb to the included amber 194 bulb, and reassemble with the clear lens in reverse order.
For the right one, squeeze the right foglamp grill (no tools needed, just squeeze in the right place) and remove the grill. Reach up through the opening beside the right foglamp (helps to have skinny arms) and pop the sidemarker out from behind. Replace the bulb and reinstall with the new lens.
Illuminated at night (photo taken with full camera flash):