Is it advisable to get a Porsche Cayenne S Tiptronic of 28000 miles and is 15 years old for 16000 dollars?

YES YES YES YES YES! realize that nearly ANY REAL EURO car is MADE to last for thirty years and 350,000 miles +! I have BMWs out there with 350K and MORE even! ANYWAYS at 28,999 miles, the ONLY THING you need to do, if you BUY IT< is to have ALLTHE FLUID CHANGED including the BRAKE FLUID! IT is RECOMMENDED at 100,000 mile intervals and YOURS here is 15 YEARS OLD! As a PORSCHE lover, I would jump on it if I still had that kind of money! THE ONE THING you must NEVER DO is to use VALVOLINE or ANYTHING other that GENUINE FULLY EUROPEAN SYNTHETIC OILS and FLUIDS! OTHERWISE you will get into mechanical troubles! The OIL must be rated A40 and nothing ELSE! PENNZOIL ULTRA EURO MAY have this rating and extends the WARRANTY out to 500,000 MILES! >>>>IF IN DOUBT ask to take this car to a GENUINE PORSCHE or even AUDI dealership for an INSPECTION. CHECK the suspesnion and BRAKING systems, and the TRANS and STEERING< etc  At 28,000 miels thsi car is JSUT BREAKING IN! It WILL get to 500,000 miels with LITLE EFFORT IF ONLY GENUINE EUREOPAN FLUIDS and OILS are used in it! TOHER oil choices are TOTAL ENERGY OIL< AMSOIL< RAVENOL< LIQUI MOLY oil! NO VALVOLINE or PRESTONE or PEAK EVER! Tehre si NOSUCH THING as UNIVEFRSALFLUIDS! Teh TRANS is made by the PRESTIGIOUS ZF company of Germant! TODAY so MANY cars out there use the ZF trannies! ANY NON S+ASIAN CAR with SHIFT PADDLES is probably a ZF tranny!  They are DIESINGED so that the PENTOSIN TRANS FLUID take up AL THE WEAR< so IT MSUT BE CHANGED at certain mileages! >>SINCE this car has suck LITTLE MILEAGE< the fluids MAY all be in OPKAY condition since they are ALL 100% SYNTHETIC FLUIDS! GOOD LUCK and HAPPY DRIVING!

Not if you don't have substantial income or savings to pay for standard maintenance from a Porche specialist and for any unexpected repairs. It also only gets 14 mpg in city driving and 20 on the open road at 60 mph.

I would question the wisdom of buying any old and fairly exotic car.  One that was barely ever driven is quite questionable.  And for for $16,000 you should be able to buy at least 2, (maybe 3) of them.

But if you are Jay Leno and need something to fill a space in your collection.....

That price is small compared to the cost of insuring and maintaining that thing for 5 years - - - unless it comes with a full warranty and dealer maintenance agreement.

If you want a money pit go ahead and buy it.

Yes! That's a GRATE price!

Assuming you can afford to run and maintain it and it test drives without fault yes.