also a sealed battery box will come equipped with an external vent

 

With that black plastic box, it doesn't move because of the bottom nipples going throught the floor, and it has a lip on all edged perfect for the battery holding it in place. With the metal mount wrapping around the top I think I meet all the requirements, I don't see any way on earth my setup would get knocked loose and have the battery shift even a inch. Maybe I need to make a vid to explain it better.

By the way, I'm not pissed or anything, critisism is important as we wouldn't want people following a method that would get them in any trouble or mess up their car.

 

You may want to passivate or paint the holes in the bottom of the trunk to prevent any corrosion from both the dissimilar metals as well as removing the primer and any other factory rust prevention if you think that can become an issue.

Edit: I also agree that the ground looks a little shaky, during startup with those long cables, it seems like that spot may be a choke point.

 

1) rerouting it on the passenger side would be much better, there's a good amount of wires going on at the driver side last time i pull mine off.

2) battery can lay down(if the cell permits) for lower center of gravity, most small cell/racing battery can be lay down. not sure about your battery but some lead acid battery will outgas, my miata has a battery with vents that leads the gas outside of the car, people replacing the oem battery with cheap battery without the vents will most likely to have a acid out trunk, not sure how it works in the s2k tho'

3)the tool well might be too far off the end if you want to centralize the mass, the spare tire location is a perfect spot. even oem spot is right between the front and rear axle, the tool well is outside of the "mid" section...

4)running wires thru metal holes without rubber gromment is asking for it, vibration can cut thru insulation fast

5) you might need to scrape up more paint for a better ground spot

thanks for taking pictures and documenting this but...

 

no no no. most bmw have them in the trunk is because most owners dont know jack shit and shouldnt try to jump their own cars. so they hide it. no joke

 

If you try to race it at all, the track inspector won't care. They have strict requirements and they stick to them. If you don't pass inspection, you don't race. Just a warning to you if you like racing.

But if you don't go to the track at all, then it doesn't really matter.

If I were to do it though, I don't know if that would be my choice of location for the battery. I still think I would have some sort of sealed box to put it in and either on the side or near the front (closer to the seats) of the trunk.

 

By the way, since you have relocated the battery in that particular spot, you should have a drain as well. I remember someone had a trunk leakage and after two days of rain... that area was like a swimming pool.

 

some older models do leak water into the trunk.

but on the writeup