Should I modify?

So I’ve wanted to modify my Jetta for a while but there are certain things that make me think it’s not worth it. 1. My car is an automatic 2. It has quite a bit of surface rust 3. It has moderately high miles(125,000 miles). With all of these flaws is it worth the time and money or should I try to find another Jetta with a manual transmission, less rust, and lower miles?