I have a 2005 Honda CRV and get an intermittent vibration in the front end when going anywhere from 35-49 mph. Usually on straight road. Lasts for say 10 seconds then stops. New tires. Alignment if good. No work has ever been done to the front end, never has been in an accident. Usually when I am going at constant speed or under slight acceleration. Happened once when I was going through a gentle right curve on the highway, but instead of seeming to be in the center or rhs of front end, then was on the left.

Best guess is to have the CV joints checked, make sure that the boots are good in the outside joints. but it could also be the inside joint just has to much wear. you are at the right mileage for either to be the problem, the next time you get the vibration put a little pressure on the steering wheel in one direction then the other and see if the vibration goes away if it does suspect the CV joints. and don't just replace the outside joint replace both half shafts. if the vibration does not change or go away when you put pressure on the steering wheel then suspect lower ball joints.

If the vibration is speed related it is most probably due to tyre balancing, even though the speed you give is a bit slow for that problem, but it is the most likely cause. Even though the tyres are new, they might have made a mistake with the weights or a weight has fallen off. Go back to your fitment center and have then check the wheel balancing again.