Welcome aboard, Raindog! Always great to have another styrene addict added to the mix. Dive in, ask questions, share experiences, and have a ball!
As to your work---you didn't say how long you've been at the hobby, but it looks like you're picking it up quickly and well. Your pieces look quite well-done as far as I can tell. My only suggestion might be to 'dirty up' the vehicle a bit---desert equipment tends to show wear and weathering pretty quickly---but that may simply be a stage you haven't gotten to yet, and there's nothing wrong with that. If you're interested you can search old threads on topics like 'weathering' and 'dry-brushing,' and your fun---and accompanying level of challenge---will accelerate accordingly.
Fun is the key: do what you enjoy, and show it off proudly. Even the most accomplished 'experts' here---and I by no means count myself among them---started out as beginners. We're all learning new 'tricks' every day, and with every project, which is what keeps the interest level high---and makes forums like this one such a great place to 'hang out.' Hope you enjoy every minute of your time here.