To sum it up in one word, EVERYTHING.
Well, all I can say it that it's OK to have other fast, high performance cars blow by you on the road, but when you have cyclists and rollerbladers easily cruising by, something is definitely wrong.
Why change a Honda Civic for an Accent anyway. It's obvious the difference in quality and reliability. Some things that appear cheap turn out to be expensive.
The Accent is a good car. Depends where and how you drive and also who drove it before you. I have an Accent that has been a taxi... in Costa Rica... And with minor investment it still runs good. A tune up every 6 months would do you good. In your situation an overhaul. If it is not too expensive for you. Well, the cars are like humans... what you give them that is what they give back. You spoil it and treat her right... It will be reliable. If you disrespect it and treat it like apiece of junk, it will eventually become one and die on you all the time.