Hey BR14,
A brother of mine has a silver Optra like yours, been with him for 2 years now and he likes it a lot. He's had some reprogramming done at Chevy Q. Ave and Bosch Super 4 sparkplugs installed to improve the fuel efficiency - he says those mods worked. Other mods he's done: 17 inch wheels, wrap around (full) skirts, EGR rear visor and "leather" seatcovers.
Here's his car with a set of wrap around skirts he got last September:
He replaced the skirts with a set he got from A-Toy last November, here's how his car looks now:
He still has the skirts from the first pic, if you are interested you can pm me.