I think this is basically a good recording, maybe a little more in-yo-face and not as ambient as original Beach Boys recordings, but you show your recording & playing competency on this. This mix sounds smoother on the top end than some of your previous mixes from 'bout a year ago, which I found too ear-searing while playing back at 80~90% full volume, my preferred listening level. I use that as a sort of yardstick when judging mixes. F/I, a classic 70's Lennon album will sound righteously good at that level, while in contrast switching to Metallica the sound is unbearable at that level. A dynamic mix holds together at that volume, and an overly heavy-compressed mix will literally fall apart at that volume, or perhaps your speakers....

Anyway, the fidelity of this mix is strong but not overpowering & pretty much in the pocket, IMO. So, kudos to you for not making my ears bleed. J/K!

I only follow covers on this board, so sorry if I've missed some of your other works! Dude, you rock, and I'd not just say that.
I don't think your basic style (as I hear it) fits this tune. Dude, you're way too manly with your energy, and the Beach Boys [IMO] were somewhat whimpy and sophomoric, ho hum. Nice harmonies, okay. Put on some tighty whities about 3 sizes too small before you do the Mike Love trip. Nah, just kidding, but I mean it! Heh.

You're capable of taking this tune to a new level,... don't make me "hint" what style I need to hear you do this in to be "authentic".
Okay,... take the tempo up about 25~30%,... mix volume about the same but manifest the guitars a lot more crunchy,... take it down to 2-part harmonies, max,... 1-2-3-4-BAM. Take out the tampon and I hope I never hear you doing MIke Love impressions again.
PS: I'm leery of fade-outs, because I generally believe they hide unsmooth endings, but I confess to not being an expert on this original Beach Boys recording, whether that would be authentic to the song. Maybe the original Beach Boys "clunked" on the ending, you never know.
I find your recordings generally good, so I can't knock the mix or your talent. Beach Boys seems like an ambitious stretch for you, so props on that. People never get tired of hearing KISS, the Ramones, Stooges or maybe Ted Nugent. That's where I see your niche. Take this tune, crank it up and make it like a Ramones or Stooges tune, and I'd bow to your genius!

/DA