Next week my 89 C4 goes in for an oil change. It is at 57,000 miles, so what else would you guys recommend having done since it is so close to 60K?

 

A few things come to mind:

If you don't know when your distributor belt was last changed, if ever, you should change it. The Porsche method is to install a rebuilt distributor , which is not inexpensive. There are several internet articles that talk to how to do it yourself, if you're so inclined.

If you don't know when you're O2 sensor was last changed, probably not a bad idea to change it - believe Bosch recommends every 30K miles.

Depending when the last valve adjustment was done, it may be time for that.

When was the last time your fuel filter was changed?

If you don't know the last time your rubber brake hoses were changed, replace them now. They're good for roughly 10 years.