--shave your throttle body-- take the intake off and use a dremel tool to thin that thick intake wall down.
--lower the car-- it always helps with handling. i put apex springs on my car, and was able to stay on my buddies bumper around 90 degree turns. he had to buy coilovers to do that for his focus
--wider rims-- i upgraded from stock 6inch wide rims to 7inch, and the i couldnt believe how different the car felt.
--build yourself a Cold-air intake-- instead of that ram air, build a CAI. i felt a big difference after upgrading mine. plus the ram air rubbed through my coolant line
--upgrade Camshaft-- not quite a DIY upgrade, but you said your dad owned a shop right?
--Clutch Kit-- shoot through those RPMs faster with a lightweight flywheel, and upgraded clutch kit.
--bodykit/weight reduction-- those bodykits arent only rice, their lighter than stock too.
--add sponser stickers-- each one will give you 5HP at the wheel
--softer tires-- better grip/bite and quicker responce. also think about upgradeing to lower profile tires, or simply stretch some normal tires. its unpopular but stretch will eliminate sidewall flex, and essentially give you a much cheaper low-pro performance.