Thanks for the compliments. I do still create similar illustrations for our shop here.
The 3/4 views give a better representation of the finished product compared to flat layout views. Indycars in particular have alot of compound curves that just don't get represented well in a flat side or top view.
We use these illustrations to develop paintschemes/livery's, sponsorship proposal art, or even arrange sponsors on an existing car. They help to streamline the design/approval process quickly.
There is a bit of time involved in creating a template however. So if it's a template we can re-use often, we'll eat the cost of developing it. ie, indycars, dragsters, or funnycars get used alot. But if someone comes to us with a one-off landspeed car or some other vehicle that isn't as popular, or no other clients would have, then the client must pay for the template should they want a 3/4 view created.