2003 9-5 Aero, ~145k miles now. Owned since 55K miles, always used full synthetic. Months ago started with a very intermittent (twice in 6 months maybe) low oil pressure (LOP) warning when car is warm. Now getting more frequent. Can still go days or weeks between warnings. When it comes on...

My '02 9-3 Turbo has recently started having issues. On a long trip I got the red triangle and low oil pressure then it died. I left it over night, came back, added 1qt of oil, and was able to start it and drive it back home without issue. Some details now. -- starts fine cold, no oil...