Subaru Visibility Rearview Mirrors/devices Interior

I notice if I quickly accelerate/go into overdrive - front of car will hum. Do I need to have something checked out?
Thank you!

2004 forester xt, strong gas smell in the cold weather when the heat is on. They won't fix it because they "can't find it" at my dealership. Do I need a new fuel line or is there an easier fix?

Thank you for these, can find a decent review now.

My 1998 subaru forester stutters/hiccups/bucks (whatever you call it) when going uphill, and when accelerating on a straight path, can it be the transmission?