1. Use a environment mapping shader
You have two options:
I. Create a static environment map from your level or just use your sky to get sky reflections
II. Create a dynamic environment map. You use bmap_createblack and bmap_to_cubemap, then use 6 VIEWs to render the cubemap from the center of your model. So you get dynamic reflections but they will cost a lot of performance

2. For roads you can use some shader effects as well:
I. Strong specular lighting and frontlights for your cars
II. Screen space reflections would serve here pretty good, afaik Superku made an implementen some time ago

Hope i could help