Kind-of off topic. A tip regarding the spark plugs. First a bit of history. When I changed my spark plugs last time, I inspected them carefully and noticed that the three plugs on the drivers side had significatant wear on the ground electrode while the passenger side plugs had very little wear on the ground electrode. I did a bit of internet research and found that our coil design (one coil powers two spark plugs) causes one plug to wear on the center electrode and one to wear on the ground electrode. The center electrode is a bit more resistant to wear than the gound electrode. So, if you swap your wires on each coil you will change the wear pattern on plugs. Once you switch the wires the passenger side ground electrodes will start wearing. I think this will allow you to get a bit more life out of your plugs.

So, after all that blather, you should try switching your plugs wires (at the coils) to extend your plug life.