Did a shoot on a Lamborghini Gallardo with three soft boxes in a garage. I am about ready to quit photography as though I have found out that all this hard work has gotten me nowhere. So this will be one of my last few sets on this forum, enjoy.
Exposures and lighting on these are far from ideal... and framing is very static on all but #1. That one could be a keeper with exposure raised a good bit. One problem is that it is floating.. the tires are so dark they just blend into the background.. it isn't grounded.. so it looks weird.
I am assuming you were attempting to shoot professionally, and are disappointed that you haven't done better? I would suggest a lot more reading and practice (possibly even working with a local pro) if you really want to try and make it work.
This is closer to what I would expect a lambo shot to look like ( a white lambo needs to be white.. not gray!)... I cleaned up some of the weird shadowing, and brightened it up.. the rear of car is too poorly lit to do anything with, unfortunately. (edit on bottom)
You obviously have a good understanding of how to produce velvety soft light, you just underexposed most of these about two stops. You also need to set your white point in photoshop. This white car looks positively gray.
Your composition needs some life, but you've definitely got a good eye.
One doesn't "quit" a hobby they're heavily invested in, so I'm guessing you have unmet professional aspirations... maybe best to flex your networking muscle and get with others in your area who you admire. Everybody starts somewhere, and photography as an industry gets more brutal every year.
Remember the old joke, "So when it gets late, how do I manage to get her bra off?", and the Ferrari owner says, 'Well, I apply a liberal dose of wine," and the next day the Lambo owner is calling the dealership crying about red wine stains all over the front of his car...