Ok, did a search not much came back. 1.) I have an 07 S40 with about 26,000 on it. I noticeda week after I got it (when it had 17,000 on it ) that there is a slight vibration while accelerating it is worse going up hill under load when it down shifts. To me this feels like it could be a bad mount, engine or transmission, or possably they need re-adjusted. My problem is I'm affraid the dealer ( I go Friday) is not gonnawant to mess with it and give me the old "no problem found" or "it's normal". My question to you all would be do you notice what I am describeing in your newer S40's ?? I just had my new snow tires put on and balanced and it didn't change at all.

2.) If I am parking the car when I turn the wheel quick the lights dim for a second and then recover to full brightness. It also does it while I'm driving if I swerve quickly. That's actually how I noticed it swerving to miss a deer and even my passanger said what is wrong with your lights. Anyone else notice this in theirs ??? Thanks for any input.

 

The lights dim probably because your power steering is 'robbing' power from the other accessories on the accessory belt, ie the alternator.
You probably notice the RPM's drop too. If it's something severe you may want to throw a voltage tester across the alt and have somebody turn the wheel. You'd have to consult some manual for the acceptable voltage drop. Or a friendly call to your local service dealer. Maybe do the same for the battery.