H15 Dashboard. Weird Glitch

So i took the Luton Bodied (Box Van to non-UK residents) -H15 and did a "low bridge" test on it. Stage 2 Supercharger upgrade so the impact was at about 81mph. It was set to clip the fibreglass/aluminum box and peel it off as you would expect. It was successful with no damage to the cab, but a very bent chassis.

I rolled to a halt and about 15 seconds after becoming stationary, a huge bang drove the dashboard through the windscreen, popped the doors and distorted the cab! It's happened twice now. Any ideas anyone?

I'll get a screenshot after tomorrow. Cab was clean and then that happened!

 

What did you use to make the bridge. I will try and see what i get. Interesting. Sounds like the Sunburst glitch.

 

On Gridmap, select the large block from the cluster of blocks to the right hand side of where you spawn, pull it to a position on the map and lower as appropriate

 

Can you show where on the box you hit it? I dont know if it matters where. A picture would be fine, unless you can describe it. Will try tho.
--- Post updated ---
I got it up to 85 MPH and tore the box off, no glitchyness. Hm..
will try more

 

It was after some time stationary it happened.





The cab was not deformed beforehand. I also tried it on a flatbed and from memory had the same random in cab explosion. This is PRE in cab explosion.