I have bookmarked many links to reference sites for cars that I intend to build.
However, I have found it important to download images and make pdf files of many of those links. Why? Many of them get shut down over time. Example: a builder's journal regarding the 1/16 Mercedes SS. Can't beat it for a step-by-step guide to building that model. But it's gone now and can't be retrieved. Fortunately, I saved everything from it.
Plus, as you know, people often clean out their image files at places like Photobucket and Fotki, and you won't see some things if you just go to the web page.
I recommend saving and downloading anything you find important in reference links to keep on your hard drive or to put into files.
I know that many of us are quick to suggest that wheels should have valve stems.
I've noticed that in many builds I've seen that the inside edges of window frames, such as vent windows, have rough edges that could benefit from a little sanding, and possibly some indication of felt window channels. I also think that some interior parts and molded-on firewall hoses etc. would look better with a little scoring around the separate parts before painting to "lift" them off of the surface a bit.
I love all racing, especially NASCAR, but I always wonder why there aren't ways for them to adapt to winding road courses other than oval tracks, such as today's Elkhart 200, and carry on in the rain. All other race series seem to be able to deal with those issues, such as Le Mans, F1, Indycar. NASCAR would be far more interesting under the circumstances the other race series face. I understand the dangers created by the incredible speeds and specialized car set-ups, but it seems that only NASCAR races get shut down this way. There must be a way for NASCAR teams and drivers to adapt to different racing circumstances.