The engine is mostly stock but I'll do my best to remember any new or improved items. All new fuses and new main relay, new Diehard International battery, new negative battery cable, new positive cable included but not yet installed, new brake bomb, new heater valve, new power steering fluid filter, all new coolant hoses (including the little ones near the firewall that are hard to install), new belts, new auxiliary fan temp switches, new coolant temp sensor, new distributor cap and rotor, new ignition coil, new BMP ignition wires, new AC receiver/dryer (AC is cold), new oil pressure switch, new oil level sensor and oil pan gasket, new valve cover breather hose, new idle control valve, refurbished and reworked fuel injectors with all new o-rings, new intake manifold and exhaust manifold gaskets, polished valve cover, polished intake manifold, polished thermostat housing, new fuel pressure regulator, new catalytic convertor, new drive shaft, new guibo, new transmission mounts, new transmission output shaft seal, new shift selector shaft seal, all new shifter bushings (though the linkage is still inexplicably sloppy), all new exhaust hangers, 3.73 limited slip differential from an E30 3-series with new gaskets and seals installed, new M5 differential mount, fairly new Bilstein HD struts mated to the stock 535is springs, new rear subframe bushings, all new front and rear suspension components (control arms, thrust arms with urethane bushings, center and end links, pitman arm, sway bar links, etc, etc.), fairly new PBR Deluxe brake pads (front rotors feel a bit warped though - common E28 malady), ATE Blue brake fluid, Metric Mechanic short-shift kit, BMP polished aluminum strut bar, BMP mylar-faced hood pad (not shown), fairly new fuel filter, new hood release lever.
Engine oil and filter are changed regularly at 5000 mile intervals. Castrol GTX 10w40 is run in the colder months with 20w50 run in the warmer months. Redline fluids reside in both transmission and differential.
Mechanically speaking, this car is in excellent condition. The items described above, if performed on a car all at once, would cost (an arm) at least $3000 in parts alone. Labor costs would add significantly to that figure.