I got a set of vent visors and want to put them on ASAP....one problem though...I asked the guy at the auto part store if the ones I bought were the "in-channel" kind (Which I want) and he said "Yeah those should be them." I go to put them on and it seems like they don't want to pop in without a lot of force behind it. Anybody put these in? Any help would be great. Thanks!