So ive been running a mag mount diamond on the roof of my truck for about two years now and honestly it works fine but i keep reading that NMO is the way to go for a permanent install. The mag mount does slide around a bit in the car wash and i had one close call where it almost came off on the highway so maybe its time.

My hesitation is obviously drilling a hole in a truck i still owe payments on. The lip mount option seems like a decent middle ground but i talked to a guy at the club last week who said lip mounts introduce a ground plane problem because youre not actually bonded to the roof properly. Is that actually a noticeable thing on VHF/UHF or is he being overly particular about it? Like for everyday 2m and 70cm use hitting the local repeaters im not sure it would matter much.

Also if i do go NMO what feedline should i be running — the truck cab is pretty tight and i dont want a huge connector situation under the headliner. Currently using whatever coax came with the mag mount which i suspect is garbage anyway.

The guy at the club isnt wrong but hes also not entirely right for your use case. A lip mount with a decent ground strap bonded to the body will get you like 90% of an NMO on 2m and 70cm, you probably wont notice any real world difference hitting a repeater 15 miles away. Where the ground plane stuff really bites you is on HF mobile but thats a different animal entirely.

That said i drilled my last two trucks and never regretted it once. Seal it properly with self amalgamating tape and a little silicone underneath the mount, done right it will outlast the truck. For feedline through the cab i run LMR-240 with the thin profile and route it through the door seal, takes maybe 20 minutes. Ditch whatever came with the mag mount for sure, that stuff is usually RG-58 equivalent at best and at 440 the loss adds up faster than you think.

i went lip mount on my jeep about a year ago just because i couldnt bring myself to drill and honestly its been totally fine. antenna is a Tram 1185 dual band which is like a clone of the diamond 770 basically and it works great. only issue i had was the lip mount clamp scratched the paint a little where it clamps but thats minor.

one thing nobody mentions — check how long the pigtail is on whatever lip mount you get before you buy it because some of them are really short and you end up fighting to get the coax routed nicely inside the door frame area. learned that the hard way.