fox,
I drew out your idea to look at it and I have to say that I'm not convinced it's your best approach.
Undoubtedly, you have saved the weight of about half the roof covering of a regular teardrop - about 20-30 pounds.
In exchange you've given away a lot of space - that mattress is 42" wide and the interior width at shoulder level is under 38", so this is a one person trailer, however romantic you are are.
And really, keeping weight down is much more about building lightly than building small. I've shown a HF-type trailer but that is one big weight that you don't really need - even the 8" wheel 990 pound capacity model weighs 220 pounds and the 12" wheel ones are nearer 300.
I think you also need to look at the problems of building this shape - are you happy calculating the compound angles where the sloping sides meet the sloping front/back? It gives me a headache working out how I would work it out! Making the front and back vertical would simplify things a lot.
That electrical space in the roof not only puts your heavy battery up high, but also is darn near inaccessible - I think you would have to mount everything on the base board and then screw that up into the roof.
If you are down to one person capacity, you could narrow the mattress down to 30" and get storage space either side of you, instead of in the roof.
The red outline on the drawing shows your Aveo in approximate cross section. As you can see, your tent-shaped trailer fits neatly into the hole in the air made by your car, but there's a lot of other space there that you're not using. To some extent, this is overlapping with
another thread about a trailer to tow behind a Miata.
Incidentally, your Aveo is called a Kalos in Britain and with either a 1.2L/72hp or 1.4L/94hp engine is rated here to tow 1100 pounds unbraked or 2400 pounds braked! However I should point out that European models will always have stiffer springs, often have bigger brakes, and always get much higher tow ratings than in North America. But it does show that your 'not recomended for towing' car is a bit more capable than Chevy make out!
Andrew