My first setup change ever was to bend the little contacts underneath the Scalextric car up a bit to reduce friction against the track.
My brother had a Scaletrix (sp?) slot car set. I remember setting up the burm on one corner so I could launch cars off it into the Christmas tree.
But, my setup trick as a 5 year old was to spray CRC on the track on a corner so I could practice power sliding around it.