Major things to look out for when buying an 04-05 Cayenne Turbo?
 

These are some of the items I keep seeing that should be upgraded/replaced: fuel pumps, water pump, plastic coolant lines replaced with aluminum, driveshaft and wheel bearings.

What are some of the other important things to look out for when buying an 04-05 Cayenne Turbo? Any recommended replacement parts? Who makes the most durable driveshaft?

I'm currently looking at examples with less than 80K miles.

Only thing I can recall that I did on my '04 TT under 100K was tires and brakes (and a lot of gas).
I also replaced the plastic coolant lines (most will have been done by now as Porsche paid for it).

Over 100K I had to replace secondary air pumps (easy job, but parts were a couple hundred). The same with the HVAC fan under the dash. Fuel pumps eventually needed replacement (seems like around 150K miles) but I would not do it until they broke. The rubber around the center support bearing on the driveshaft failed at 180K miles and needed a $10 "fix"...so driveshaft seems overkill...but some do it (replace the entire driveshaft and bearing).

At about 175K, it needed one of the window regulators replaced (motor was still good) and front lower control arm bushings were shot...so I replaced those with a kit that upgraded to Turbo S ones. Also, a couple of light bulbs have gone out and a couple of fuses (related to the secondary air pumps and fuel pumps when they went bad).

Wet sanded my headlight lenses and polished them at about 150K (were a bit foggy). They look like new now. Somewhere along the line, I replaced the battery once. Seems like it was around 125K miles.

Thank you Flitstone! Very helpful and greatly appreciate the feedback.

No problem. One thing about these is that they require some special tools....but if you have to pay for all the work you get done, Porsche mechanics are really expensive and some tasks take a lot of time. Parts are certainly more than they would be for a Ford. My biggest concern now is that no one seems to rebuild the engines. I like mine enough that I would happily pay a reasonable price for a rebuild when the time comes...as my body, paint and interior are in very good shape (like many I see). I guess that since I am near 200K miles...maybe there just isn't much of a market for that. It seems that the older ones like mine go for anywhere form $7K to about $20K...so maybe folks just get another one if the engine craps out badly as a professional rebuild is likely between $10-$20K for remove/rebuild/replace...and the car is a paperweight (parts) without an engine.

It has a crappy nav system...but, I use my Iphone. I also wish it had a back up camera. It is great for towing.