Hello Group - 1999 Toyota Corolla LE

Hello Group,
I am the relatively happy owner of a 1999 Toyota Corolla LE, automatic trans with overdrive, - fully loaded. I was very happy to find this car with no rust and only 91,600 original miles. It is a beautiful red - venitian red pearl - I believe is what Toyota calls it.

I was pleasantly surprised to find out that this car is the first to come with the aluminum block and laser etched valve guide seats. I also really like the look of the lower roof as compared to the post 2002 cars. These qualities lead me to think of this car as the Low Aluminum Corolla. Has anyone else heard of nick names for this car?

The sun roof has a sun shield of sorts over the front. Does this serve any purpose? I want to take it off as I feel it may be adversely effecting my fuel mileage. Any feedback here?

Which leads me to the only disappointment that I have with this car. I'm currently getting 29 miles per gallon(about 320 miles per tank). This was a bit of a shocker as I thought it would surley do better than 30 mpg. Also, I am coming off of a 1991 Geo Metro Convertible, manual trans, which would get 42 mpg all day long any road city hiway, whatever. The spark plugs are brand new and the tires are fully inflated. Does anyone have any experience improving the fuel mileage on these cars? Please advise.

Thank you & Happy New Year!