Dashboard lights go out on Infiniti M35X - 2007 Infiniti M35x

low brake fluid due to worn rear pads is most common.

https://parts.infinitiusa.com/ get you pads from nissan, those are the best by far.
Also you can use the Maintenance advantage or Nissan value advantage to save even more. These pads include needed hardware and are ceramic for around 68 bucks!

usually its one of the wheel sensors is gone if in canada go to local part source they can scan it for u and tell u which 1 is gone

Its possible you just tripped a code. Take a OBDII scanner and scan for codes. Its possible that if you erase the codes, they wont come back and all will be well. Write down the codes in case and if it comes back look in to them. Maybe abs sensor.

Change the relay located on the backside of the fuse box on the drivers side.

Have a look at the dashboard lights dimmer switch. That switch, losing contact momentarily while the lights are on, will cause the lights to flicker.

have the rear axlenuts retorqued and noise should go away.other noise under hood not ringing any bells.

You have the latest generation of Nissan's 3.5litre motor (just before they released the 3.7litre). Its very high reving and high perf'. Your 3000rpm at 70mph is normal, I have an Acura MDX 2004 with a 3.5litre Honda motor that does about the same, and I have an Infiniti M35x 2007 that is about the same.
You'll know if its straining if the gas mileage is bad. Watch the mileage as a good indicator of drivetrain issues.

We found a local dealer to install a battery for free as long as we bought the battery from them, I think it cost us less than $10.

Ironically I had the "!" inside the "U" come on this morning as well in my 2007 M35x. Oddly this is indicating that you have low tire pressure. I suspect this is happening due to the temperature change. At least for me as I live in New England and it was very cold this morning.

I too have an 06 M35x and just had to replace the driver side valve cover gasket. It was leaking toward the rear of the valve cover, as well as around the cylinder 6 spark plug hole. Hope this helps someone.