On the backside of our
eyebolts, we used
Takata's backing plates.
The plates also have a
small hole already
drilled into them.
We put a rivet through
it to make sure the
backing plate doesn't
spin off the eyebolt and
become loose.
Despite whatever mounting method your cousin's mailman may have spied at the local import nights show, no real sanctioning body will allow you to drive without properly supported shoulder belts. To ensure the shoulder belts maintain a consistent proper angle with the driver's shoulders, a harness bar, roll bar or roll cage must be used.
And roll cages only belong in one place: racecars. The human body is a soft, fleshy sack of cells, able to stretch a surprisingly large amount from the phenomenal force of a car accident. It doesn't matter how far away you may think you're sitting from the halo bar; if you're not going to be wearing a helmet all the time, don't drive a car that has metal bars in the cabin.
Unless you like smashing your face into a metal rod and splattering it like a watermelon hitting the pavement, don't use a roll cage in your daily driver.
So then, the choice for an autocrossing street car comes down to a roll bar or a harness bar. Cheaper than a roll bar, harness bars are also much easier to install. Both bars necessitate the sacrifice of the back seat (as a roll cage would), but roll bars offer rollover protection versus a simple harness bar. For those in advanced open track sessions or time trial competition, a roll bar is the better option. Just be sure to do a proper job of installing some manner of force-dissipating backing plates or supports to the underside of the roll bar, lest it punch right through the thin floor panel during an actual rollover.
There are some e-thugs floating around the Internet who are only too ready to provide claims that a bucket will not drop backward in an accident like a stock seat (which would allow you to dodge a collapsing roof), and that a harness will keep you stuck upright in a rollover and, thusly, dead. To those geniuses-please stop stealing all our air.
The purpose of a modern OEM-designed occupant safety system is to prevent cabin intrusion (no collapsing roofs), hold the occupants within the cabin (no ejecting from the car), and upright within the primary (seatbelt) and secondary (airbag) safety systems. OEM engineers don't like unknown variables and factory seats are designed specifically not to have the seatback fail and fall back. This would send an occupant's body away from both the seatbelt and airbag, and allow them to bounce around inside the cabin, with untested effects.
Even worse is the myth that harnesses don't allow you to move around and duck in the event of a rollover, as a factory three-point belt would. Much like the previous scenario, cars are designed to keep the occupant upright and in the proper seating position, in front of the airbag and held by the seatbelt. Plus, in a car crash, it's highly unlikely that you'll even be able to think fast enough to duck if your car is rolling over. Speaking with a few Mitsubishi OEM safety engineers and an employee of Sparco USA has only reinforced our beliefs.
With the Sparco seat/Buddy Club rail, M1 Fabrication & Development harness bar and Takata harness in place, driving is much more direct. There's no need to hold ourselves up during cornering, allowing us to focus more on driving. | 
The lined-out sections indicate the range of proper angles within which a harness belt may be installed safely. Pay special attention to these angles when choosing the mounting points for the belts. | 
Project Evo IX's windows look perfectly clear to the naked eye, but the 3M Crystalline tint is claimed to block over 99 percent of UV. This shot was taken with a circular polarizer filter to show the difference. The large window ( right) is untinted. |