so ive been putting off doing a proper mobile install for like two years now and finally got around to it last weekend. threw a Yaesu FT-7900R in the dash and ran the power direct to the battery with a fuse holder, that part i feel pretty good about. the antenna is where im second guessing myself.

i mounted a NMO mag mount on the roof but i couldnt get it dead center because of the sunroof, so its sitting maybe 8 inches off center toward the passenger side. been reading that you want it centered for a good ground plane but honestly i dont really know how much that matters in practice. the antenna itself is just a cheap Tram 1185 dual bander, nothing fancy.

radio seems to be working fine, hitting the local 2m repeater no problem and even got into one about 40 miles out on 70cm which i thought was pretty decent. SWR checked out okay with my buddies meter. just wondering if anyone else has done an off-center mount and if its actually causing any pattern issues or if im overthinking this whole thing

Honestly you're probably fine. Off-center mounts are super common especially with sunroofs and moonroofs in the way, and yeah the radiation pattern gets a little wonky but in practice for hitting repeaters it really doesn't matter. you'd have to be doing some pretty serious weak signal work or maybe satellite stuff before that asymmetry would actually bite you. the fact you're getting into repeaters 40 miles out on UHF with a mag mount and a Tram antenna tells me everything is working the way it should. i ran an off-center mount on my old jeep for three years and never noticed any real world difference. if you ever do a permanent NMO hole drill through the roof you can get it centered then, but for now don't sweat it.

nice, the 7900 is a solid radio for mobile use. i had one for a couple years before i upgraded. one thing i'd double check is how you routed the coax — if it's got a sharp bend anywhere near the connector on the antenna side that can mess with SWR more than the placement will. also what length antenna did you go with on the Tram? just curious because i've been looking at those for a second vehicle