if the car needed coils, you'd know it-misfire, check engine light, etc.

as far as 100k-like i said, mb says they'll go 100k, but i've had earlier mileages where the coils were suffering from overdrawn amperage because of the worn fr8dpp33s. change them at 60k and there won't be any coil or wires issues. got 2 cars with almost 200k ea and they have oe coils. 3rd set of plugs though and another set due at 240k, if i see either of them again. good luck, chuck.