Very impressive stuff here! I'm glad I took a peek to autemo after a long time. Unique works are always more interesting to look at, especially when it's been well thought out and the effort shows.
First of all, I love the design on the front. I can see the similarity to Koenigsegg as well. Similar shapes and proportions happen unitentionally so I don't see any point in shouting about a missed listing of a Koenigsegg in the references. It's definitely not a copy and, to me, the front looks better than the Agera's. I love the headlights, I love the front cover and the little crease details on it.
A small pointer about the front though.
Thinking about how it would be best if it was built in reality. This way you could avoid the super-sharp spike on the bumper where the air vent module is set. Those parts are critical when it comes to smoothness of the surface. Without the spike that corner would be more rigid, thus ensuring a smoothly flowing reflection. Easier to manufacture too.
Great work on the rear view too although I'm not feeling it as much as the front view. It does have a lot of sweet shapes in there (I love the tail lights!). And also, I should mention, the edge of the rear bumper is exactly what I was talking about on the front bumper. So, it seems you know what I mean about that. Maybe you just overlooked that when making the front?
Looking at the rear view for a bit longer it starts to settle in better. Still not as sweet as the front though. At the moment it looks like none of the lines on the side connect to or parallel with anything on the rear. Here's an idea:
(EDIT: Just noticed. The edge of the side vent does somewhat parallel with the edge of the rear diffusor.)
Another pointer to think about when making concept cars as realistically plausible would be to think about how and where the license plate would go, especially on the rear because at least the rear license plate is mandatory everywhere, as far as I know. It's also a nice detail. It's pretty easy to imagine where it would go on this car but the angles of the surfaces don't really support that at the moment. Nitpicking to some extent as well but as you're working on such a high level with these I thought I'd mention that too.
Dashboard looks fantastic as well. Seems it's got all of the instruments in there. Looks easily plausible as is. Maybe a slightly wider black stretch for the edge between the interior and the exterior paint would have been in order (for the window glass and it's rubber sealing. Currently it looks so very thin. Another nit-pick.
Congrats on getting it to HOF! Well deserved in my book.
"it looks similar" 
