OK, I will help, as I have a Series 2, or had one till Tuesday as it was sold for $25,000.
External Differences.
S2 has different bonnet, front bar, rear spoiler front quarters (more squarer), boot lip featuring skyline logo are color coded.
Internal Differences.
S2 has dual airbags, some have ABS, different trim inside, mostly the same as S1 just those cosmetic differences. Different warning lights on dash as well. Also features 6 x 9 speaker covers on rear shelf, but still a round 6" speaker within, just a bigger looking cover.
I sold my S2 with 63,000 km, and some nice mods for $25k. Spewing because I needed the money and had to sell now. Had a been a bit financially better off, I'd sell it in March/April, when prices keep rising and imports dry up.
Also, you wont see a flood ever again, thats what RAWS was brought in to prevent. On the LVI scheme, only a few thousand vehicles should come into Australia. Last year alone, over 20,000 vehicles came through to Australia, prompting investigation and a system overhaul.
Plus local second hand sales fell, as young people and old, prefered to spend 10-30k on a range of low mile, good quality, high performance imports ranging from silvias, 180's, Skylines, etc.
Why would you buy a second hand commodore?? thats the whole point, they wanted to protect the local industry.
So buy a skyline or import whilst you can, because it will get harder and harder, and before long, the only way to get one will be to privately import directly from Japan for yourself.
Paul (I miss my GTS-t)