We have questions like this every once in awhile. The obvious answer is that you can do this. but the real answer is if you are ready for the consequences of that action. "Many of the chemicals found in nail polish are the same found in auto body paint, albeit in smaller quantities." (2009, tierramianailindustryexposed.wordpress.com) The important parts of that statement are that the ingredients are in smaller quantities which means that the paint or polish is less potent. It also says that many of the chemicals but not all of the chemicals are present in the polish. Both of these facts show that the polish would only be a temporary fix if it was successful at all.
"Finger nail polish does work...in a pinch. Permanent markers can also work in a greater pinch." (n/a, Priest).
Notice how finger nail polish is stated to work right next to permanent markers. The use of those two things in the same breath underlies the problem. The problem is the quality of the fix. It will be apparent that something is "off" about the vehicle and then it will become more apparent when the person comes close to your car, truck, or SUV. Keep in mind that those getting close to your car, truck, or SUV will be people you know, care about, or want to get to know further. You have to ask yourself if it is worth the embarrassment.
The other thing that no one talks about is how it will affect the vehicle after the polish is applied? If you are going to use touch up paints or have someone repair the area, then is it going to cost you more to do it because you used the polish. If you do it yourself then you will probably have to remove the polish with sandpaper or polish remover. The internet is mixed on whether or not exposure to polish remover damages a vehicle's paint. You must make a determination if you are willing to risk that in order to have a temporary fix.
The other thing you need to remember is that even though nail polish and car paint might have similarities. They are still not the same. If a color looks the same, it still may not look the same when it is on the car. If it is noticeable, then you will have a hard time removing it later. You could end up damaging the car more than it already is damaged and spending more money fixing the problem than you originally intended to spend. Many people would use finger nail polish as a cost cutting activity, however, it may not save you money at all. It may cost you more money than what would have cost you before you used the nail polish. It is the risk you take, but if you are cognizant of that possibility, then you should be okay.
Tired of looking for paint codes? Use our new touch-up paint system for GM made vehicles. Just click here to use the system.
Priest, Darren. "Car Paint Scratch Repair Tips from the Car Detailing Expert." Car Paint Scratch Repair Tips from the Car Detailing Expert. Http://www.best-auto-detailing-tips.com/, n.d. Web. 23 Dec. 2015.
"Automotive, Car Paint Contains Same Chemicals as Nail Polish."Automotive, Car Paint Contains Same Chemicals as Nail Polish. Tierra Mia, 16 Aug. 2009. Web. 23 Dec. 2015.