As Jan suggested, I did some longer runs. Really trying to take my time and slow down but seem to struggle getting consistent penetration. I think I've read on here changing to 0.8mm wire from 0.6mm might help?
Is that 1.0/0.9 mm steel? 0.6mm wire will make a big difference.
Good practice running beads but you will only do that on the chassis/underside of the car. If you look at how distorted that panel is you will see why for thin body panels you use the stop start technique.
Looks like your off to a good start on thin stuff the angle and distance of the torch, stick-out and heat of the workpiece itself make a huge difference in penetration. There is such a thin line between not enough and too much heat. It's confusing and frustrating in the early days as there are so many variables to deal with.