Radio controlled hobby cars are just like the real, life-size ones; they need regular check up, cleaning and tuning and an overall proper maintenance to guarantee good performance while on the tracks or whenever it is used.
You can simply use a denatured alcohol in cleaning your RC car(s) but be sure that it doesnt get to any of the electronic parts of your car since this type of alcohol has a very strong solution which may be enough to damage parts of it. But if you want to go beyond just by using denatured alcohol, you can try other products that may give you benefit though can also leave you spending more than the allotted budget.
There are still more options which you can take though so you dont have to be stuck on spending a lot on solutions you wouldnt be needing everyday. An alcohol and a bottle spray can do the trick. Air compressors are also great tools for cleaning your RC car. The thing with air compressors is that it blows off air to the RC car but it doesnt do the entire maintenance needed for your car. If you dont have an air compressor yet, better save up for it because it could cost around $65 69 as the market price. But if you already have one,...