Is it normal for a 2011 Honda civic to have loud wind/rattling noises at about 65 MPH?

I'm test driving a 2011 Civic. I like the way it drives, but I took it on the highway and when it reaches 65 mph it makes a loud noise it sounds like wind blowing through the left side of the car. The faster I go the louder it sounds. Is that normal. I have been driving the dealer crazy for over a week now.

Could be that the left door… Front or rear on a 4 door… Is not sealing tight to the body weather strip… Might be from a poor previous accident repair… Or some wind noises/rattles can come from high speed wind patterns around outside mirrors/loose mirror body or glass, etc… Have a bodyshop check and adjust the door to seal better if needed and check the outside mirror or other windshield seals. A common trick is to slip a dollar bill between the open door and body seal, close the door and pull the dollar bill out… If it slips right out, the seal is not making good contact and door or window frame should be adjusted inward… Should be a little drag on the bill… Repeat the test in various door seal areas. Often times you can roll down the door window and brace a knee against the inner door trim… Tug on the window frame inwards by hand and then recheck the dollar bill test to help it seal better. I've done that on countless wind noise complaints.

Check for any signs of accident repairs… Mismatch paint, weld marks, overspray or rough paint edges, etc. Or do a VIN check on the vehicle /Carfax or call your insurance agent with the VIN to see if their records show any claims on it. Insurance companies can access a database of claims on vehicles to see if they had previous damage which might total the car if a new accident occurs… Or to be used in a new claim on repairs that might not have been fixed properly.

In your profile it said the car was in a wreck and fixed.Bad body work is common because the customer is final quality control. An easy way to check for air leaks is to fill the car with tobacco smoke and watch where it comes out.Turn the heat all the way up because hot air expands.Police do this during car searches so drug dogs get more scent. They are grinding you down to make the sale.

Honda's aren't known for their quiet cabins.

Find a different car!

Hi so it has an issue so why buy it.

I had the same problem with an older civic and it got worse on windy days. After several weeks of efforts to fix it (I masked door seals, air vents, mirror edges, windows edges and hundreds more points) the conclusion was that the windshield adhesive was defective at a small area where the noise came from. Any temporary fix was a waste of time and the only solution was to visit a specialized repair shop, have the windshield removed to peel of the old adhesive and re-glue it to its proper position with fresh adhesive.
You could check if you have the same problem by doing the following experiment: go to the highway with a friend sitting at the passenger's seat, as soon as you reach the speed you can hear the air noise the co-driver will start pushing the windshield hard (from the inside of course) with his hand -firm pushes, not punches- not only near the source of noise but on many random points. If you can hear the pitch of noise changing even by little during any of these pushes then you found the source of your problem.
Notice: maybe it would be wise to try it first before you hit the highway because if the defective adhesive area is larger than expected, then pushing the windshield from inside may displace it and you don't want this to happen at 65mph.