Re: lexus lights for a 155
Because an Alfa isn't a Lexus. Lexus lights only look good on Jap cars and the 155's too old to get away with it, it'll end up looking like a dad in bermuda shorts.
And as EA says, doesn't the 155 have a red strip that goes with the standard lights across the top of the numberplate? If that isn't being replaced you'll end up with clear lights paired up with a big red strip across the numberplate and it just won't work.
But then that's just my opinion, if that's the look you're going for it's your car, you do what you want with it.