I did many trips in the 1990s while being in the military.
When I went I always had to stay over a weekend so I would drive to one or two Belgian cities to take in the sights and be a tourist. I do not remember seeing any Muzzies except for a few when I was in Brussels.
I also was there in the 1990s. Our experiences are somehow inverted. Maybe it was the particular places we went to.
I did go back in December, 2009 and was struck by how many more—or more open about it—they were than before.
From Wikipedia:
Islam is the largest minority religion in Belgium, practiced by an estimated 6% of the total population. The practice of Islam in Belgium is relatively new, and is mostly observed in the Belgian immigrant communities.
Since 2009, Mohamed is the most popular given name in Brussels and Antwerp, Belgium’s two largest cities.