I have seen in some Mustang parts catalogs the shift lights listed by themselves. Can these be used alone without an aftermarket tach. I would love to have a tach and shift light that I can actually see, but don't see a good place to mount a 5 inch tach. The dash plate holding the two middle air vents might work depending on whats behind it. Hate to drill holes in the top of the dash itself. And I want a mounting that won't be shaking all the time. None of the parts catalogs I have looked at mention anything about mounting hardware.