what can I do that won't mess with my CPO warranty.

[albojoe]

I have 2010 m35x with ext warranty 10year/100k I have 32k now. Im wondering what I can do to the car without giving the dealership a reason to give me a hard time when I actually need something done under warranty in the future.

[Larz]

Congrats on getting the warranty. Although Infiniti makes a very reliable car, you will definitely get your money back in warranty repairs as everything is a fortune to fix / replace on these cars.
It's best to check your copy of the warranty agreement for disclaimers or contact them directly and document who you spoke to, date contacted, details, etc.
Having said that ... Anything you change, modify, or add to your car will generally NOT be covered under the warranty. Also, any other parts of the car that might be affected by your modification or installation will also NOT be covered. For instance, if you change out speakers, amps, or add an interface for your I-pod, etc - they might not honor anything related to your entire audio / video system because you 'tampered' with the original factory set-up.
I have an extended warranty as well (from CarMax) but they WILL warranty aftermarket mods and added equipment ONLY if it is installed by a CarMax dealer (and I imagine there are exceptions to that bit as well). It's possible that your Infiniti warranty may have the same feature.
Just remember that warranties are actually insurance policies and they are treated similarly - the goal is to sell you the policy and then try to minimize pay-outs when possible. I would be nervy about doing things like cold air intake, plenums, suspensions, etc that could give them en excuse to deny coverage on a wide variety of other parts connected to, or dependent upon the part you modified. You won't want them to deny all coverage for anything engine related just because you added a spacer or intake tube.

[seldomseen]

Read your extended service contract's terms and conditions carefully...to understand what will void your extended service contract. e.g., aftermarket accessories, failure to properly maintain the vehicle as per manufacture's reccomendation, et cetera.

[svard75]

to put it simple. Anything you modify or change will no longer be covered under warranty. There are also some dealerships that will refuse to repair other parts which are directly related to your modification. For example if you install headers onto the stock exhaust system and your cats blow up, they will not honor the catalyst warranty because the headers created additional stress on the catalyst.

In other words if you are given a hard time visit another dealership.