Usually the under carriage is covered, as a result you wont see any of such spills on the floor unless their is bucket loads of liquid leaking.
By the way you got a good deal for the parts replaced, last year I had to change similar things at it cost me around 1K, youre lucky man, lol.
dear NURV.. at first yes.. then i take out the under tray and monitor one night no sign of coolant leak on my garage floor. then when i start the engine coolant come out like waterfall then i realize that my thermostat KO already. have to change already.
First and foremost ask the seller to provide you with complete service detail of the car, you want to see if the car is serviced at regular intervals. I usually ask the seller not to drive the car if possible on the day of viewing as I want to start the car from cold and see how it starts or if the engine makes any noises. Another thing you want to check if the car is driven regularly, as a car that is not driven regularly might develop problems.
Request the seller to allow you to get the car inspected by a professional and a reputable mechanic, get the mechanic to do a complete diagnostics and physically inspect the car. Proceed only if the car is in good condition, having said that it would be a good idea to replace transmission fluid soon after purchase. One last thing, make sure you check the error/fault history in ECU and look for any errors related to active steering, this is a very common issue with E60's.
Bro, youre buying a BMW, everything will be expensive