1970 Datsun 240Z — windshield replacement created a highway whistle

This is usually cheaper to test than to guess. Two 1970 Datsun 240Zs can feel identical and have different causes, so measure before you copy someone else's repair. Save the big job until that test fails. This is from a 1970 Datsun 240Z in Phoenix. I'd want that in writing, not as a promise. Checking again after work.

If it were in my driveway, get a real battery/charging test on the 1970 Datsun 240Z, not just resting voltage, before blaming a module. If the cheap test changes it, stop and reassess. This is from a 1970 Datsun 240Z in Phoenix. When does it actually happen? Not trying to scare you — just skip the expensive first guess. I'd rather look cautious in this thread than stuck later.

I wouldn't throw parts yet. Loaded-suspension checks on the 1970 Datsun 240Z catch play that a wheels-hanging inspection misses. That's the branch I'd chase this week. Do that first. I keep a notes app thread for this now.