1987 Porsche 911 — steering wheel shakes only under highway braking

Ask what changed right before it started. Swap the cheap/easy piece first on the 1987 Porsche 911 and see if the fault moves. You'll know quickly if you're on the wrong tree. Any freeze-frame data saved? Make the next action something you can finish this week. If the story changes I'll post the new data.

Intermittent stuff lies if you only catch it once. Two 1987 Porsche 911s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. On “steering wheel shakes only under highway braking,” that was the fork that mattered for me. Have you gotten a second quote in writing? I'd rather pay for diagnosis than a second guess-repair.