For how many miles does 2008 Dodge Avenger SXT last?

I'm planing to buy this car.
Have 110000 miles and the price is $6000
my concern is that i wouldn't be able to drive this car for many years.
I'm planing at least 5, and i'm planing to put around 100000 miles more.
I would appreciate your knowledge and experience
Thank you

What happens if I block a return vent?

So my dorm suitemate likes to keep the unit warm, and I like it cool. I want to block the heat from getting into my room in the first place. I have two vents, one of which I'm assuming is the return vent. What happens if I block that one off? I understand that the return vent is what brings air into the ducts to be heated or cooled. If I block that off, then there's no air to condition in the first place. But will that cause problems, or should blocking the other vent be enough to keep the heat out?

2006 Ford F150 Lariat 2WD, 5.4 L V8 Triton

I am a girl getting a lift for pure appearance. I do not care about off road performance, I just want my truck to look good in the cheapest way possible.