Firstly let me say straight off the bat that I'm not worried about "Stance" or "Filling out the guards" as they are looks based and not handling/performance based things.
I've been reading things about offset and scrub radius like the following:
If I'm going to up the wheels from 14" to 15" and the tyres from 175/??/14 to 195/50/15 then I know that wider rubber will make it feel different, but if I want good precise handling and the lowest possible tyre wear shouldn't I be looking at factory offset wheels (ET45 in my case)?
If I get wider wheels then they'll fill out the guards better (y0) anyway.
If I went to ET30-40 on an early model MX5 then how much can/does wheel alignment need to be changed to compensate for a different front track? What will it give me in terms of stability with a wider track? Can someone describe to me what they mean by 'tramlining' when they talk about changing things? People talk about 'tramlining' being bad but to me it sounds a little like 'handling like it's on rails' which to me sounds good.
If I want it to drive nicely and be well behaved at parking speeds and I'm not worried about handling on a racetrack should I just get some ET45 wheels and make sure the wheel alignment is inside tolerances before putting new rubber on?
I want the setup of the car (alignment, wheel diameter, offset etc.) to give the tyres their best shot at lasting a long time no matter how it's driven.