Tact and maybe asking directly with a PM? I have sent someone a PM first asking if they want some pointers or tips, especially if it is a model I have built and have some knowledge of. Am I a pro builder no. This is a tough line with a forum or even a contest. I run into this with the real 1:1 cars, people ask to have a car judged, or what is wrong with their car, and then are all bent out of shape when they are told something is not right.
With a lesser quality build, tact is key. People need to offer suggestions on what would make it better without criticizing the person themselves. I still run into new builders at shows that will ask about BMF, or where did some of the detail items come from. It amazes me if you talk to people at show, not the ones you know already, but the people looking at particular details on kits, that they may have never been to an NNL or large show where they find out what is out there. You can get great conversations going and sometimes get someone to another event and that gets them excited and trying to build better. Telling anyone their work is bad or junk never helps anyone.
How about the Gremlin kit? Engine poorly detailed. Engine bay parts that just kind of floats around in their and has no diffinitve mounting points, the front header panel too wide for the body. Chassis has no mounting points that touch for the final assembly. Seats that look too skinny for anything. Built it for the Buckey challenge and that was a few hours of my life I will never get back!
I remember helping my Dad work on a 60 Thunderbird. Was the first old car he bought. Went to look at a lot of cars with him, and I know he always wanted a 55-57 Bird, but with 3 kids he had to get a 4 seater. Was thrilled when I was able to buy the car back and still own it today.
Winged Mopars are my next favorite. Went to the Hoosier show at Indianapolis with my family when I was 10, the Thunderbird meet was held there. We got to go on the track and I remember seeing a club of winged cars there on the track as well. Really like the 68-70 Road Runners, the cartoon character, the beep beep horn, and the colors.