Is there any way I could make a 2000 Nissan Altima look more "modern" without ricing it? And what are some generally affordable ways I could tune it?

My grandmother's 2000 Nissan Altima was given to me not too long ago, and because of her pretty bad vision, she barely ever drove it. It only has about 20,000 miles on it and before it was inspected, my mom even had the original tires swapped out with new ones. It's a great car; it's in amazing condition and it drives really well, the only thing is, I want to make it better. I wanna do something to improve the performance (NOT SWITCH THE ENGINE, THAT WOULD BE WAAAAYYYY TOO EXPENSIVE), and even do something to the body that would make it look newer, but I also don't wanna ruin the cosmetics by accidentally ricing it a bit trying to make it look newer. So first of all, what can a 16 year old like me do to a car to not only tune it, but make it look nice and sleek (if that's even possible). via /r/cars http://ift.tt/2sGGrA3