I know there are a stickies, search, and countless threads on these but I have to ask...

2005 SL stock, with intake only, 102K miles; regular oil; regular maintenance

Plugs/coils
What is the best plug/coil combination to replace the OEM plugs with at 100K? This is a daily driver with mostly highway miles. I was thinking of getting new coils and plugs just for maintenance reasons since I plan to drive the car into the ground but would not mind adding in some $ to get better mileage/performance. I had a 4th gen and NGK-plat was the way to go but seems like plat/iridium, etc does not matter much for 6th gen.

Brakes
Same here; need new front pads but if there is a reasonable upgrade in pads and/or calipers and pads that anyone recommends I'd be up for a modest upgrade. I don't like to use my brakes often but we all have to stop sometime...

Tranmission cooler
After 100k, any reason to install one? I was supposed to get one quite a while back but just never got around to it. No issues with tranny just don't want to have problems down the road.

Thanks for any feedback

 

Change the plugs with the OEM NGKs. If coils work, do not change them.

Brake pads depend on your driving style. For normal driving style autozone will do.

I do not see a need for transmission cooler.

 

The car comes stock with NGK iridiums...
I think 100k miles on stock plugs and coils are proof enough they do the job pretty well. I would stick with those. I have Denso Iridium Power http://www.globaldenso.com/en/produc.../features.html IKH16 plugs.
I also have a trans cooler on my car. Heat is any transmission's enemy. Longer life with a cooler transmission.

 

stock plugs are platinum. I did stock plugs at 90k still looked good. are iridiums 100k? thought they ran shorter.

 

I stand correct, thanx Nismo... http://ngk-sparkplugs.com/plfr4a11-p-2974.html These are the stock ones which are platinum not iridium.
http://www.densoiridium.com/faq.php here is some info on Iridium plugs.

Some iridium plugs are meant for performance, while others are meant for long life. It really depends on what you are going for. I have the performance ones which last 60k miles.

 

The big thing to remember is to keep your tranny fluid clean. These automatics are notorious for self destructing with bad fluid. Keep it clean and levels up, and you will be just fine.