Two issues. One, it doesn’t work well on most cars because the aft tape measure generally won’t clear the undercarriage without interference. Two, there is only total toe, no zero or centerline, so the steering wheel will usually come out crooked. This requires trial and error to correct; add to one side and subtract from the other. But I still find it useful enough for getting it close enough for steering gear replacement before sending the customer to a tire shop for a proper alignment, if you can find anyone who knows what they’re doing. I can’t.