The 528i is one of the nicest of all the E39's in that it has a nice spread of power, economy is not that bad especially if you throw in some open road cruising, reliability is excellent. My car has done 199 000 and is also a 1998 model and the only abnormal thing that happened was at 156 000 the head cracked in two places. Fortunately i was pulling away from a stop sign when the needle of the temp gauge went into the red. I stopped immediately, towed the car to my brothers house which was about 500m away (i was visiting in Upington at the time) . First thought it was the thermostat as the bottom radiator pipe was cold. Replaced with new BMW part, filled up with water and the next morning at 5 i left for home, 900km away near Cape Town. Drove all the way here with one eye on the temp gauge. Needle stayed normal all the way. Cut a long story short, a BMW mechanic did the job after hours and all in all with the head stitched welded, pressure tested, etc., cost me about R7000 to have the car back to normal. Since then it has been running like a swiss watch. Other items to watch are the front suspension components. Had to replace the upper rear wishbones (of all things) because of worn ball joints. Tappet cover gasket was another thing i changed (had the car since 108 000 km and 4 and a half years) I still enjoy the drive whenever i get into it. Oh, also replaced the front shocks at about 194 000km, only because the one shock started sweating. On the open road returns 11,7km/l at genuine 120. In town about 7km/l (it is an auto)