Actually now-a-days its more of a low-poly, uv-mapped model first, then high-poly, high-detail version of the already uv mapped model second, then a render of this second model into normal, ambient, and other maps that can then be applied to the low-poly model.
My two cents:
Model:
- Wheels should be slightly bigger
- Wheel wells should be more arched and tighter around the wheels themselves.
- Back fender sticks out too much
- Front fenders need to be flattened on the bottom a bit more
- Back wheels moved backwards more
- Slightly longer cab
Texture:
- Not nearly enough detail in the main texture. Very blurry
- Dirty up the bottom of the main texture, to look like its been driving over some rough terrain. Mud splashes, scratches, bullet dings, whatever it takes.
- Rocket needs a lot more detail and dirtyness. Looks like its just had it's vertex colours set right now. Add some labels to it, warning text, brushed steel, and if you figure it out, an occlusion map to make it shine a bit.
- Right now its pretty obvious all you did was took a planar map from the side of the model and textured it. Thats why you're getting those long stretched texture lines on the inner parts of the model. Instead, select the two sides and planar map them / overlap them so you only have to do the texture once and it'll mirror over, then select all of the faces pointing up and planar map them, then the front and back should be a seperate planar map, and finally the bottom if you're feeling ambitious, otherwise include the bottom as part of the top if it wont be seen. Basically a box map would work a lot better.
- There's next to no detail on the mechanism that lifts the rocket up, looks like you just coloured it brown with vertex colours. Texture it.
Now, I dont know what you've already done so most of this might be irrelevant. Like you said you were still mapping it so most of my texture issues may be fixed on your own. Either way just keep all of the above in mind.