Im going to weld it but im trying to find out if it is made out of steel or alumunium. Thanks.

 

I highly doubt it is aluminum, so it's gotta be steel.

 

It's steel alright, no ways is it going be aluminium, even the S2000 has only the fenders and hood made of aluminum.

Besides, you cannot weld aluminum to steel chasis, so either the whole chasis is aluminum too (no ways dude) or it is all steel.