Tee Nuts you can get at the bolt bloke or even Bunnings. Just make sure
a) Italian ones they are great , buy satin ones , if they a polished shiny stay away from them ,the spikes break easily. Then if your going to use 3/16 inch i recommend retaping the thread actually retap any one you get , you'll thank me latter :) Bed the TEE NUT into the timber by puting another spare piece of MDF with a drilled hole then a bolt with a big washer. DONT use the amp to bed the TEE NUT.
Second drill the hole in the MDF of your baffel with the shank size of the TEE NUT.Again you'll thank me latter :)
Use only thin MDF that way it wont raise the carpet too much then all you have to do is little holes in the carpet for the bolts.
The sikaflex is very strong. Thats why use thin MDF as the MDF will rip off the Sikaflex if you want to remove it latter but the Sikaflex will have to be cut off

Thanks for the info and tips.

Cheers

I'm trying to decide how my sub enclosure will be fixed in position behind the passenger seat. I'm definitely putting it on top of the raised box behind the seat, and I'll definitely be building it out of MDF with black carpet wrapped around it, but I'm wondering how others have attached their enclosures behind the seat?

Ive welded a bolt to the wall behind the seat. Slide box in, do up nut the screw the sub in,

I've got a 10 inch pioneer slimline sub in an enclosure built to fit behind the passanger seat. I just used those adhesive velcro strips on the bottom and rear of the enclosure. Don't think the sub has moved an inch and it's been in there going on 2 years

On my car there is a lip ontop of the factory Sub box.

I made my box a snug fit so it doesn't move at all.

I like the velcro idea, that would be very simple and effective for normal driving. I wonder whether it would be sufficient on the odd occasion when I go to track days though?

dasic1's idea sounds very robust, but a little more tricky.

I don't think I'll find a better solution than either of those anyway, thanks guys!

you could weld a nut to a piece of steel much like a harness backing plate and have that slipped in behind the firewall carpet.
then just bolt the box to the nut through the carpet. and when you want to remove it, you can just undo the bolt, remove the box, undo some clips and then pull back the carpet and remove the backing plate and nut...

Please can i get into this discussion as it is very dear to me.........
1ST MUSIC IS SO SUBJECTIVE...........
If you like what you have so be it BUT if you want it to be accurate , well thats another issue.
Have you listened to any systems in MR2's ?
This really needs to answered because i cant help but get so sad at seeing a car being butchered :(
What are you goals ? What do you want to accomplish ?

Mandylay -

Is there an alternate for good bass using the JDM placement in the storage compartment behind the passenger seat?