Honda, Sony, Mercedes engineers all use metric right?

All autos sold in the US since at least the early '70s have used metric fasteners exclusively in structural parts, and power train parts have been nearly all metric.

The SAE (Society of Automotive Engineers) that was/is the primary US source for standards for automotive parts and equipment changed their name to "SAE International" several decades ago, and their publications have included SAE/Metric (dual dimensions) in all articles and reports since about then. More recent publications (for 20 years or so) have used the metric specs with only occasional "translations" to equivalent "US" or "inch" terms.

For vehicles other than some UK designed airplanes anything other than metric nuts and bolts has been obsolete (in the US) for at least 40 years - and often longer.

The only "real metric" tool I can think of that you can't get easily "off the shelf" at Smears and Screwyabucks is a screwdriver (but most of the critical sizes/styles for those are proprietary and dimensionally identical regardless of what you call them).

John