Hi Reuben,
I'm a fulltime automotive photographer based in Australia, so I'm probably qualified to give you some feedback!
I'm going to start with the positives, your panning and car-car tracking stuff is good. You clearly are working on it and trying to get slow shutter speeds to really convey that motion. Your edits are nice and simple (and realistic) but still have your own style to them.
I'd say the biggest thing you need to work on is intent. You want to work with the big automotive brands? You need to show their product without other cars or distractions in the shot. There are plenty of shots in your portfolio that I see other photographers, other cars, other stuff in the shot.
When a company hires a photographer it's because they are looking for someone who can promote their product and make it look special. So in my mind this means that the car is the hero, but remember it's the brand too. For example - the tracking shot of the orange 911. It's a nice shot, the shutter speed is nice and low, the wheels are blurred, and the car is sharp. BUT what brand is it? You're a little broadside with your composition, you have to make sure that you can see that badge on the front.
Now into the short sharp nitty gritty of your portfolio.
-Ditch any photos that look like they are at a car meet
-Ditch any double ups (i.e the interior shot of the 911, I'd keep the vertical as the horizontal has too much external body in it.
-If the pan isn't sharp get rid of it - mostly looking at the Lotus Emira and yellow 911
-Ditch the shot outside the dealership or swap it for one that has the words Porsche not cut off
-The red Lambo with the doors up should be your opening shot. Easily the best of them. I really like the idea of the one shot through the tree but I'd have gone lower to bring the foreground closer to the car and less of the top of the tree branches so they don't overlay the car.
-The two shots of the Lambos by the castle(?) are more or less identical, ditch one and level the horizon in it. Try to get all the lines straight (horizon, castle wall etc etc)
In your portfolio though, I'd want to see more of a mix of images. I want to see action shots (tracking, panning), shots of the car in various angles (front, back, side profile), as well as smaller things like details of badges, wheels, engine shots. A car isn't just what's on the outside as well, show me that you can take photos of the interior, the screens, the seats, the details that the designers spent time on perfecting. Remember your are helping to sell a product and that includes all the bits that people use on the inside!
You're doing good stuff, I used to run a small team of photographers doing automotive and your stuff is on par with them in some regards - but you still have a way to go including the points I mentioned above.
If you want to chase the commercial photography dream then look to what the brands actually use, follow commercial automotive photographers on instagram, use Behance and search "automotive photography". Check out the magazine shooters (Aston Parrot, Mark Riccioni, Mark Fagleson, Olgan Kurdal). Even from Australia check out Alastair Brook, Teddy Airey, Cristian Brunelli, Chris Benny.
Look at the work they do, try to figure out what makes it good, then try to replicate it. Nothing wrong with finding your style through copying others.
Per shoot I am for 1 or 2 that the client considers great, as long as you have something they can lead with in the usage or campaign. The rest have to be up to your own professional standards.
But any photographer will get a bunch of "safety" shots which are bread and butter that hit the brief then you can start being more creative, different angles, apertures, shutter speeds etc.
How many shots do I get per year that I consider great?
None haha - my favourite shots are usually pretty technically imperfect or revolve around a technique that won't garner mainstream appeal. I work in commercial photography and technical imperfections are only really allowed within certain constraints.