I think I'm getting fumes in the cabin

I have a 2010 with 5k miles - bought <4 mos.

Last week, I started noticing a petroleum smell in the cabin. I've also had trouble with the inside windshield. When I tried it wipe it, it just smeared. Finally, I used some cleanser and it's clear. It took several applications to work.

I read in the Gen II forums about a loose oil filter cap. I checked mine today. I was able to turn it about 1/2 inch.

Now, I'm getting headaches after I drive for more than 15 minutes or so. I've tried switching the circulation but I can't tell which way is better.

I'm due for my 5k service and it's paid for but I thought I'd check here first.

Also, I have a choice of dealerships for service. How do I find out which one is better?