I have just been reading up on some old threads about racing seats, but im still confused. I know that making your own set of seat rails will have to be engineered, but I found this company that makes straight bolt on seat brackets to the magnas floor pattern. Will these still be legal or will they still need a cert?

I would say you need to get them engineered as it would depend on the seat, not just the rails

JDM_TE, what was the places names?

Perhaps they have had them certified already?

If not they should have a disclaimer like, 'for off-road use only' etc

this is the website, there made for diamante's of the same year - http://www.yourhotcar.com/product/list/Mitsubishi/Diamante/Car_Interior/Seat_Brackets/
i would use a ADR approved seat

How much do the Ralliart Magnas seats weigh & what do some lightweight performance seats weigh?

How much do the Ralliart Magnas seats weigh & what do some lightweight performance seats weigh?

I weighed these... let me look around for where I wrote the weights down though.

I'm pretty sure it was 14kg per seat - Ralliart seats. Let me confirm though.

if you are using a recaro style seat yes you do need to get them engineered. however idealseat can make up a set.
this should explain it:

http://www.youtube.com/watch?v=15EpilY5Xbs