Hey, Simon - it is good to have you back in the mix...

I don't know all of the specific details of how an E is different than ITS version of the e30 but yes - you can update to run the faster class. HOWEVER, you've got to end up with exactly the same specs - every single part - as would have been on the car had you started with the "i" or whatever.

And the e30 325 is more competitive in its class in A than it will ever be in S. Ever. I'd seriously recommend going the ITA route if you decide you have to build...

...but saving your dough and buying an already prepared car is still going to be more affordable, if you compare apples to apples in terms of level of preparation.

K