Rusted or rusty?
They're both adjectives which I suppose to have the same meaning. Thereby I'm finding it hard to use them correctly. Here are the following statements which got me confused about it:
This car looks rusty.
I would never get in that rusted car.
I hate your mom's rusty car.

Question

Rusted or rusty?
They're both adjectives which I suppose to have the same meaning.  Thereby I'm finding it hard to use them correctly. Here are the following statements which got me confused about it:
This car looks rusty.
I would never get in that rusted car.
I hate your mom's rusty car.

Answer

The phrases "rusty car" and "rusty tools" are more common than "rusted car" and "rusted tools."

Here is a Google N-gram frequency chart.

https://books.google.com/ngrams/graph?content=rusty+tools%2Crusted+tools%2C+rusty+car%2C+rusted+car&year_start=1800&year_end=2008&corpus=18&smoothing=3&share=&direct_url=t1%3B%2Crusty%20tools%3B%2Cc0%3B.t1%3B%2Crusted%20tools%3B%2Cc0%3B.t1%3B%2Crusty%20car%3B%2Cc0%3B.t1%3B%2Crusted%20car%3B%2Cc0

Answer

I would personally use them interchangeably. In your two example sentences rusty and rusted work equally well. The only time when I can think that this would not be the case would be if you were using rusted as the past participle. For example, you can say “the car had rusted by the time I bought it” but you couldn’t say “the car had rusty by the time I bought it.”