Been reading one horror story after the next about spark plug replacement lately. Apparently our design is horrible at best. Our car has just shy of 48,000 miles on it. Do you guys recommend changing the plugs at this mileage? If so, is it for chance of them NEEDING replacement, or for preventative purposes to avoid possible breakage with even higher mileage down the road? It is an '06 which by what I've read is when 2 piece plugs were still being used. Thoughts?