A few times gone through. Very unspectacular.
In 2010 I was on an excursion to organic farms from Alsace (Prüm) in Luxembourg. It was a bit more exciting than in the 80s and 90s. Very German and actually nice landscape.
We were with about 20 people (Klaudia also) of the 3rd sheep and goat conference on a dairy goat farm, a walnut farmer with Texel sheep and a cheese dairy. Lunch in the village community house, which was not heated and only 5 degrees warm. This impression remained to me.
2014 briefly in Luxembourg at the transit France - Belgium (driven over Schengen). Fuel was very cheap.