One other thing I just remembered, about driving in Brussels - well a couple - first and most important and I acknowledge the broadness of my brush, Belgians drive like idiots. They don't signal, they cut across lanes, they stop for no reason, their lane control is sometimes best described as vague, yet the place is crawling with speed cameras waiting to send you a fine.
Second - the kerbs (curbs) in Brussels specifically are higher than I have seen anywhere and they are sharp. When you open your door you may well scrape the bottom of the door or dent the bottom of the door and that will result in a charge at the rental place. Take lots of photos.
Third - the road surfaces range from OK if they have just been redone to downright awful. I often avoid the free highways in Belgium to spend tolls and time going around through France. You can't do that on your route. Make sure your fillings aren't loose. The worst is Brussels to Liege.
Fourth - Luxembourg drivers are like a cross between Belgian and German drivers - and geographically that's true - who drive like lunatics but much faster, regardless of speed limits. My guess is that some must be EU diplomates commuting between Strasbourg, Luxembourg and Brussels - the three centres of EU government- so therefore don't worry about being seen by the cameras. I just let them pass...