Incredible 20/4/10 Rule For Buying A Car References. The 20/4/10 rule of thumb for car buying helps you shop for a vehicle that will fit your budget. The next part of the.

Just remember to think of the 20/4/10 rule as a guideline, not a. The 20/4/10 rule can be an excellent rule of thumb when buying a car. It’s simple, and it works for many people.






