Yes, it's easier, but making side mount brackets at home is much harder than bottom mount.

Keeping two square bolt patterns inline, both side/side for tranny/door clearance, and front/back for foot/beer belly clearance was difficult enough. Trying to keep track of all that plus back/forth tilt and having one of the bolt patterns in another plane doesn't sound fun.

depending on the width of the seat and the size of the "feet" on the side mount, you will not be able to line up the side mount on the steel strips and the 2 humps in the floor.

Ultimately you probably could, but on the driver's side I wasn't able to get the last bit to fit. 2" was too wide and impacted on the transmission tunnel, but 1.75" wasn't wide enough to get the bolt holes to line up on the stock mounts. so therefor, I just cut the rear humps and then made a 6"x4" plate backing plate and bolted it to the floor.

I was more thinking the commercial side brackets you can buy to match the seats. I thought they had a lot of room on the bottom part of the "L" shape to match whatever spacing you owuld need but sounds like I am wrong.

As far as the tilt, that is taken care of by the commercial brackets having multiple postioning holes pre drilled.......isn't it?

Well, like I said, some may work and some may not work. I was able to get my passenger's side to work fine, but the driver's side a lot more difficult thanks to our tapering transmission tunnel bullshit. You will just have to try it out and see.

The tilting can be taken care of. if you have multiple holes then yes it will be taken care of. If you don't you can always add some. Also, if you cut the rear humps, you will have some angle naturally added in.

Even with the stock humps left in there is a little bit of angle.

I have side mounts installed using strap steel/aftermarket side plates. It's difficult to get to the trans tunnel bolts after the seat is in so I install it assembled. Only difficult part was beating in the trans tunnel/door panel to get the seat to fit straight.

Ah, yes, premade brackets. Thought you might be making them yourself, which sounds like no fun.

Whatever you do, I'd suggest buying something like the MOMO Start (newer version) which has both side and bottom mounts, so you have a variety of options.

Solution:
https://www.miataturbo.net/attachmen...ine=1322788908

I hammered it plenty, but I Guess not enough. waht size hammer did you use? and did you hammer at the front mount or what?

I didn't have to, with a first gen MOMO Start, although it's slightly off center, making it a little painful on my arthritic knees.

The slightly off-center part is what I can't stand, and with bad knees I'd put up with it even less. No way round that but to do it proper. It's either a lot of work or costs a bit to have someone do it, but it is 100% worth it. My Sparco Circuit is an incredibly narrow bottomed seat, and still, with the butt 1/2" off the tub, to center it the trans tunnel needed alteration.
I'm a die-hard DIYer and on a tight budget, but that was one thing I was happy to pay to have done. I don't think you'd regret it.