2C takes 13 frames to come out, and has three active frames. That seems like a pretty small timing window especially since the ice car has a variable time before it hits you based on your distance. If you can do it consistently, be my guest, but thats not something I would rely on.
IB->2A->236A->combo seems much more consistent to me.
I might be reading this wrong from jins move data you should be able to even punish his A version of the ice car consistently if you IB. (it says -7 on block, 2A comes out in 6 frames)
As for j.d versus 623C, that sounds like its really dependent on your height at the time of the attack. Might work if you're at a low IAD height (higher up you will block it but not deal damage, and fall straight down, leaving room for jin to punish), but even then you can't combo off it. Is there a better way to bait and counter this attack?