Every 3-4,000 miles;
1. Spark Plugs (replaced, not re-gapped)
2. Air Filter
3. Oil Filter.
At 30K miles, dash cracked and only in winter, the right side of dash would turn an ugly brown color. "Dash-mat" cover came in handy.
At 60K miles, replaced all hoses and belts, whether needed or not.
At 90K, replaced Electronic Computer Module. Faster chip. All Fuses and replaced battery with more powerful battery.
From about 120K to 130K miles, I replaced the water pump, the alternator, the battery, and the electric fan.
At 140K miles, A serviceman at 'Oil Can Henry's' broke the upper plastic radiator hose mount by pulling hard on it, that led to the following:
A new radiator, water pump (again,) thermostat, hoses.
160K miles replaced both head gaskets.
Fuel Pump at 165,K.
Headliner at 166K.
*Never use SPITFIRE spark plugs for more than 3K miles. I used mine for almost 4K miles and they had gotten so hot, all, but 2 broke apart when taken out. (you could tell a noticeable difference in power - about 10 to 15% increase - for about the first 1200 miles or so.)
*I have never had so much fun in any other vehicle, as I've had in my INDY.
*The stock stereo was more than an excellent sounding stereo, with surround sound.
*The suspension system on the INDY was an upgrade from other models, and although a bit rough on rough roads, it handles sweet on smooth freeway drives.
*The Yellow color made it hard to resell to just anyone, but yellow is now becoming "in style," which is nice.
*The INDY interior was even nicer than my 1987 corvette, and felt a lot like a real Indy car.
*The quick agility and steering saved me from quite a few accidents, as I've been able to steer away from them, even at higher speeds, (90-110).
*The leather steering wheel, gearshift were a nice touch, although the door panels all, but fall apart at the top, (very bad design!)
*Doors are too flexible when windows are down.
*Hood should have been designed to lift with hydraulics.
*Air cleaner lacks enough air flow.
*Air cleaner Boot, (from air cleaner to air injection system) need to be raised away from engine farther.
*Tons of room for front 6'-2" passengers, yet rear passengers had better be three-year-olds, for lack of leg room.
*All in all, this car is very peppy, and most of the time you will feel as though you are doing the speed limit, when in reality you are going 10-15 miles per hour faster. Very smooth.