I will likely gusset some areas near the control arms, not sure what you're worried about around the driver's seat. The car will have a "body", and yes, this will be street legal in the US.My spidey senses are tingling while looking at the thin-wall square tubing near the upper control arm mounts and around the driver's seat.
Not for street use in the US, correct?
As a NC state certified safety inspector, I must respectfully disagree with you. The thinwall tubing would not fly in this state.The same rules that apply to go-karts apply to cars.
I consider 16 gauge frame to be WAY too thin for street use. I use 12 gauge minimum for gokart/minibike use. Most road legal frames are 1/4 inch or thereabouts.
Exhaust pipe is 14 gauge. 16 gauge is thinner than quality exhaust pipe. You asked, I answered.
That is my opinion. others may disagree.
Safe bet it’s not HREW…The front half of a Top Fuel dragster is made from .060 wall tube.