4 point racing harness for daily beetle?

I've got a 69 bug with very punchy motor. Now the seat belts in it are very old and tatty and need to be replaced. Rather then just replace the lap belt I was thinking about going a four point harness just for a little more support over the shoulders.
The downside to this is I have the back seats in the car and I do plan to use them. Now I know you are not meant to mount the shoulder straps to the floor behind the front seat because it can cause spinal damage in the event of a big crash but its a bloody beetle after all, if you are going to crash it at speed you are rooted anyway. I really want the four point harness just to keep myself and my passenger from sliding around the car. Here's what im looking at (http://www.ebay.com.au/itm/2x-4PT-H-Style-Blue-Racing-Nylon-Straps-Seat-Belt-Safety-Harness-Universal-/131143114738?hash=item1e88bd1ff2)

Open to all opinions on this so fire away!

As long as the belts have the ADR approval tags attached they can be used, the shoulder straps are meant to be as horizontal as possible and all the belts I fitted came with the instructions detailing the allowable limits , three points are easier to fit and will do the same job, both my cars cannot carry passengers legally due to the fitment of the belts and are plated as two seat vehicles, mounting points will need to be engineered.

vwo60 wrote:As long as the belts have the ADR approval tags attached they can be used, the shoulder straps are meant to be as horizontal as possible and all the belts I fitted came with the instructions detailing the allowable limits , three points are easier to fit and will do the same job, both my cars cannot carry passengers legally due to the fitment of the belts and are plated as two seat vehicles, mounting points will need to be engineered.

I have no issues with rego/police in my area so im not worried about it being legal. How did you go about mounting the belts behind the rear seat? I may even make up a quick release for the rear if I want to carry passengers and just use it as a lap belt when someone is in the back

I fitted the correct size compensating plates under the rear window, The RPM belts have a quick release on the three point harnesses were the shoulder harnesses join, so the belts are easy to remove, also have eye bolts mounted to the floor, I am glad I engineered mine as the legal issue is not only with the police or rego, do not buy your belts from china as they are not complied and could not be relied upon in a crash..

I seriously would never fit harness to the back wall of any vehicle. Possum Bourne lost a navigator in an accident from crushing of internal organs when the hit a tree and the belts mount not to a harness bar causing them to crush the navi in the seat. Any accident passed the front doors could easily do this when they run to the back of a vehicle for fixings. I would also never trust a VW beetle rear firewall.

Yeah decided to just go with normal lap belts. if I crash the bug im rooted anyway, hahaha!

I have a engineered bar behind the rear seats the belts are fitted to in the correct line. I really do not think it matters were the belts are mounted in a beetle.