You can use slot racing display cases. You can find them in slot racing stores, you can put a complete team (11+11) in it I think.
If you just want to put two or 3 figs in it, little jonnhy lightning/autoworld slot racing display cases are great too. I made one (with a small turf on it) for a friend with a couple of collectable figs on it.
For individual figures, John TVchachi found a great solution using baseball display cases.