Driving speculations

Recently I started getting 28-30 mpg from my 2000 Toyota Camry, which took some major changes at first. After doing a load of research on hypermiling and other tips from the internet, I tweaked and adopted the practices which I thought were most practical and effective in my case.

Since I have a bigger car than most economical cars out there, some of the techniques of hypermiling were not options, such as turning off engine every time at a fresh red light.. as opposed to cruising to a stale red light.
I switch to neutral everything I approach a red light that has recently turned from yellow. I'll be stuck there for a good 2 minutes in the daytime with other traffic, therefore I figure why not release the load on the engine while you're stopping or dead still. THE KEY TO BETTER GAS MILEAGE for any car... is slower acceleration and conserving the braking distance. This does not necessarily mean impede traffic, although people behind you for some odd reason feel the need to rush to a red light and sit for a good 30 seconds, while I cruise on by and the light turns green. Even if it makes little sense to do what they do, they don't realize it or make the effort to change their driving habit. Imagine going 50+ miles more on the same amount of gasoline and money you spent at the pump. Just leave the house earlier and drive smarter people!

Today it occurred to me to replace the replaceable air filter to a K&N air filter that is self cleanable, and provides better air flow. I use synthetic oil and it definitely makes the engine run smoother and seemingly stronger. Last year I had replaced the spark plugs which was a job that called more attention to detail than most car jobs.

What is in the future? lowering springs and replacing the struts/shocks for sportier ones? I generally take hairpin turns which involves a lot of bodyroll which I have become accustomed to and actually depend on. Therefore I was wondering what difference a lower ride will do for my tire life, handling, and ride quality.

I wonder what difference the new air filter will make, in terms of mpg and torque feel. :)