The renders are good, but not that interesting. They're lacking a good ground shadow to really place the car in the scene. Also you could try going for a more interesting angle, maybe some closeups with some depth of field.
im holding off on doing fancy renders until the end when ive done the cars i have planned to do, otherwise ill just get bogged down...this setup is just something i cobbled together to work with whatever car i chuck in there without having to mess around with it...im going to do some big group renders, i took a massive batch of reference photos of the Bathurst pit straight/grid area when i was up there last year
Love your old touring car collection and you have great skills, its nice to see someone that loves their Holdens and Fords too!!!!, also I think any car can be cool if you have the ability to make it that way!!!!!!.