The problem with wanting a database of only the good mods, or wanting a guide of such by select people is that everyone has different requirements and standards. As an example, I am not massively fussed about graphics and interiors. I drive using bonnet cam so the vast number of interior issues that others struggle with (analogue gauges not working, mirrors flipped, reflective windscreen, bad steering/shifting animations and rain/wiper issues) doesn't bother me at all, whereas it can be deal breaking for a lot of players that play from the interior camera, especially in VR.
What I am interested in, is that the cars are enjoyable to drive and the performance is as close to real world performance as possible. Someone mentioned Legion's blog as possibly being a good source for them to get their racing cars and it can be just that for many. However for me, Legion's blog is a good source for the models and the base physics, but because of the BOP between his car groups, I have to go to work on their data files to get them closer in line with reality. When I want close racing and balanced grids then I stick to series that are well balanced in real life, like modern GT3. Mid-Late 90s GT1 and Can-Am were not well balanced, they were generally uncompetitive, especially between the front and back of the grid, so for these cars, I've had to make adjustments. I accept that I'm likely in the minority in my requirements and wouldn't complain or expect Legion to change his whole blog purpose just to suit me, I'm grateful it's there as a source of vehicles that I can then tweak to my liking.
The best thing that you can do (if you have the time), is learn the basics of editing a mod. Once you can do that, then you can start working towards your perfect game. Otherwise I'm afraid it's as someone else said, you're just going to have to go by trial and error and get ready to hit that delete button for every car that doesn't hit your personal requirements.