so ive been running a mag mount diamond SG7900A on my car for a couple years now and honestly its been fine but im starting to get annoyed with the cable routing and the slight scratching on the roof. thinking about doing a proper NMO mount but my car is a 2019 honda civic and drilling into the roof feels pretty permanent and honestly a little scary.

someone at the club mentioned lip mounts as kind of a middle ground — you get a decent ground plane without drilling but supposedly the connection isnt as solid and can cause issues with SWR or just intermittent problems over time. has anyone actually used a lip mount long term on UHF? like specifically 70cm, not just 2m where i feel like you can get away with more.

the other option i guess is just finally committing to the NMO drill and doing it right. i have a diamond NR770HB sitting in a box i bought like 8 months ago and never installed because i keep second guessing myself. trunk lip, roof drill, or just stay on the mag mount — what would you actually do here

drill the roof. i know it sounds scary but if you do it right with a proper NMO mount and a good waterproof seal its really not a big deal and youll never look back. ive had lip mounts on two different vehicles and both times i eventually got intermittent ground issues that showed up as slightly elevated SWR that would change when i hit a bump. not terrible but annoying. on UHF especially you really want that solid ground connection, the wavelength is short enough that ground plane quality actually matters more than people think.

just get a good chassis punch, measure twice, use some self-etching primer on the bare metal edge and a quality mount like a Larsen or Maxrad and seal around it with some silicone. ive had the same hole in my truck roof for 11 years with zero rust or leaks. the NR770HB is a good antenna too, just get it properly mounted and itll work great.

honestly i went with a trunk lip mount on my accord and its been fine for two meter FM which is mostly what i use it for. cant really speak to 70cm performance specifically but i havent noticed anything weird. the cable does sometimes creak a little in cold weather where it goes over the lip but thats about it.

that said i keep telling myself ill eventually just drill and do it properly. the mag mount is probably still your cleanest option if you move cars a lot or dont want to commit — the scratching thing is real though, had a friend put foam tape under his and it helped but then he had a slightly worse ground and his swr went up a bit. kind of a tradeoff no matter what you do