I have a 380 ES series 3, already done the Galant intake, Berklee muffler and going to lower my car with superlows up front and lows on the rear. Only problem now is the wheels. Admittedly I would love to get 19 or 20 inch rims but I just cant justify spending 2 grand that I don't have to basically just make the car look better and potentially ruin the ride. I currently have stock 16 inch alloys and I was considering getting them powder coated black, would that make the rims look smaller than they already are?

To be honest I would put superlows in the rear aswell cause its gonna still sit pretty high but that's your choice. I was running 225/55/16s on my standard mags before I went to 18s then back down 16 again, the extra little bit of width made it look better and it gives you access to the more performance style tread patterns like the ku 31 pattern from kumho.

The only alternative is 20's!!!!

They aren't nearly as bumpy as some might think......

Mine rides smooth as on king superlows all round.

Mine sits on SuperLows front and Lows in the rear, because 380s (and Magnas) sit higher in the front, and the car will sit evenly all round done this way. You can still put SuperLows in the back, but scrubbing has been an issue for some people.

Agree, Superlows up front & lows in the rear look just right from what I've seen.
18 or 19's look nice on 380's - maybe look for a set of good condition second hand rims.

Wider wheels

Superlows front & rear with 19s is what I have. No issues with scrubbing and I'm happy with the size of the wheels. Admittedly I do want to go lower and that may cause some scrubbing issues but I'll deal with that when I get to it.

I agree with kif, there's no substitute for 20s! I've got a tj and a tl, tl is lowered on 20s, tj has stock sports suspension on 17s, and the tj has the rougher ride. Go second hand, you can pick them up for roughly half new price if you look around.

I currently have stock 16 inch alloys and I was considering getting them powder coated black, would that make the rims look smaller than they already are?
Not sure they'd look smaller, but for the $ to get this done, why not put that money towards a good, used set of 17s? The 16s look very small on the 380 (as well as being a very plain style) and a carefully selected set of 17s will look better for around $500-600 or less.

For the above price of 500-600 you should be able to pick up some 17inch forged wheels with tyres let alone regular 17s

18's FTW on lows

Dished rims usually look smaller than flat-faced rims. So if you want the best visual appeal, don't get dished rims.

You could also go a slightly smaller tyre than standard. eg I have 235/40/18s on my TJ VR-X. I bought these tyres because they're cheap (common size), but they're about 10mm smaller than the standard tyres. The ratio of sidewall:rim makes them look much bigger than the 1" upgrade in rim size. I'm not suggesting you do anything stupid, but if you have the choice of tyres that are slightly smaller in diameter than standard or slightly larger, go the former. Less sidewall will make for a firmer ride though.

At the end of the day there's not a whole lot you can do - I would just suggest getting a set of second-hand 17" or 18" rims and tyres second-hand once your current tyres wear out.

Just upgrade to a set of GT/VRX or SX rims they look way better than the poxie 16s people always get rid of them

I see the OP is in Victoria - Mal (Madmagna) is always wrecking 380s, so it'd be worth hitting him up to see if he has any of the above rims.