Highway speeds

Just curious if anyone has noticed that the car wants to hunt around on the highway? Seems like I have to make constant small steering corrections to just to continue driving in a straight line.

I noticed that my tire pressure was about 43 psi on a fairly cold tire. I dropped it down to 35 psi and on the highway, it usually goes up a pound or two at most. I still notice it wanting to jump around on the highway.

Just wanting to see if it is a tire issue, or it needs to go back to the dealer.

And I guess since I am posting, I will ask a few more questions about other little problems. LOL.

When I take off from a light, and get to about 30-35mph, and let off the gas a bit to maintain that speed, I notice a jump in rpms. I feel a slight pulse when the rpms do that. Not sure if its the motor doing it, or the tranny? Is it the torque converter locking up? Or is that water in the tranny?

The other issue is with the A/C. It seems like it only blows cool air when you are moving. It never really gets real cold even when moving unless it is cool outside. Is that normal?


Any input is greatly appreciated.

BTW its a 2006 300C. Has 940 miles on it.


Thanks

Shawn