You want to look for Car Wars Compendium Second Edition, either the blue cover First Printing (known as CWC 2.1, published in 1990) or the black-and-green cover Fifth Printing (known as CWC 2.5, published in 1996). Both versions are out of print, therefore you will have to search used game sections of game and book stores. Copies appear occasionally at moderate to high prices in the Realm of Chaos called eBay.
Once you have the Compendium, you can use whatever scale you desire. All playing materials for Car Wars are out of print, except the Fifth Edition sets you mentioned, therefore you need to create your own components like smoke clouds and mine counters.
1X Scale (BattleCars, Car Wars, Formula D): 1" x 0.5"
1.5X Scale (Micro Machines)
3X Scale (Matchbox and Hot Wheels)
8X Scale (1/24 Scale Models)
Drop me a note if you want to discuss the subject further. I have a few Car Wars resources on my Web site. I am hoping to perform a badly-needed update to the site next month.