That is an interesting car, because it shares it platform with the Kia Stinger which launched in 2018. So technically, while the first year of production for Hyundai it was built on another assembly line for Kia. In fact, there is an article on line compariing the two cars and the differences offered between the two of them (they are there, but not very great):
In regards to reliablity, all we have to go on is the first year of the Kia Stinger. Since the reliablity of Kia and Hyundai is almost always lockstep together, it is pretty safe that one car's first year reliablity will indiciate the other car between the two brands (the engineering department is the one and same as they share engineering).
Since TrueDelta no longer tracks reliablity neither car is listed. All we have left is Consumer Reports which is biased statistically but besides that is not biased. According to first year reliablity, it lists average overall. It notes slight issues (more than 1% showing an issue, but less than 5%) with suspension, brakes and body integrity (squeaks and rattles). My guess is people drive these sports cars hard, and in doing so, knock a few parts a little loose while at the same time pushing the suspension and the brakes. I don't think the cars are inherently unreliable. In fact, for sports cars, they are probably very good reliablity. I say "probably" because there are two caveats. One is that we only have one year of reliablity from a sister brand. The other is it is a sister brand and does not necessarily mirror the G70 which is a little bigger than the Stinger. However it is probably close.
Last, it is a brand new car. So finding a used one for under $40,000 may be really tough to find. In fact, doing a national search for the G70 the cheapest used 2019 is about $43,000 and it has the wrong engine from what you want. If you really want a perfomance car, go for its sister - the two liter turbo Kia Stinger. You can get the 2018 for just under $30,000 anywhere in the country for 2018 - and it is well in your price range. That is if you really like this powertrain and platform. Since the handling is top notch (nearly as good as the european brands) for a lot less money. The powertrain and performance with the smaller engine is excellent as well. I test drove the Kia Stinger last year and it drove wonderfully, but was too small in the back seat for a family of four.
There are other options of course but others on this board can talk about them - I focused on your question. Best of luck.