you want to use duct tape and tape the seam on the airbox. i just heard of this and looked at mine and theres a huge crack snow and kevlar belt dust can enter in.
then you take off the shelf under the hood and get door foam weather stripping, i put some everywhere that two parts met together. then i took the headlight out and put the foam around the headlight just before it peaks out the hood.
then you want to use some electiral tape and tape the drip hole and headlight adjuster knob on your dash.
the flashlight trick is you put a flashlight pointing up in your airbox and anywhere you can see light when your hoods closed snow will enter.
the other option is kind of what i thought of..............the airhorn on the shelf i took off and then i wrapped with slp prefilter material, and used a zip tie to hold it tight and glued it then re insalled it so there is leftover filter material sandwiched between the shelf and the horn, this way if the zip tie breaks it cant fall in the lower airbox
this way if anysnow gets in the upper airbox it cannot get into the lower airbox. and if any of the foam gets loose it wont go into the motor.