[CarJunkie]

Hello, I am new here so I might as well introduce myself and ask a question. I am a true CarJunkie, and want my kids to be also.
　
I do not yet have one of these great cars, but I am seriously considering getting one and would like some input from those who are using these cars for autocross and track, hence posting in this sub-form.
　
A little history:
My previous fun cars have included a '99 Civic Si which was heavily modified. That got replaced by a 2005 WRX STi, then a 2005 Mazda Rx8, then my current 2011 BMW 1M which I have had since new. I auto cross a few times per year, but my real love is track days. The Subaru got sway bars and a typhoon intake, but otherwise stayed stock. The Rx8 stayed completely stock except brake pads for track days. Once my 1M was out of warranty, I got bit by the modification bug and have done full exhaust, tune, coilover, front sway bar, camber adjustment plates with proper alignment, dedicated track wheels with R-compound tires.
　
My oldest just got his driver's license in October of last year. I wanted him to learn how to drive a standard, but the only manual I owned when he got his permit was the 1M, which I was not going to let him learn with. I bought 1986 (e30) BMW 325e for that purpose, and that has allowed him to learn to drive a stick and something that you cannot get in much trouble with. It is a pretty cool car, but has had a lot of little issues that we are slowly working our way through. It is fine for street use, and we did an autocross for the first time this past weekend, but I definitely would not trust it for a track day. He daily drives my wife's old Prius, LOL.
　
Despite the e30 being slow, he had a blast at the autocross and would love to do it again. I think he would like to have a better chance of being competitive. In addition, my wife came out to watch the afternoon and said something to me that I never thought I would hear come out of her mouth. "Maybe he would like to do a track day with you."
　
That is my dilemma. I would definitely not trust the e30 for a track day, and am debating whether I would let him drive the 1M, which is essentially non-replaceable at this point. I had already given consideration to what kind of car I would want to get if he liked autocross and track days and would do them with me. I am not a fan of open top cars especially for novices, so Miatas are out. In my opinion, the FRS/BRZ/86 platform is the best option.
　
I would plan to keep it set up to be in stock class for auto cross. I would love to get some input from you guys on whether you think this car is appropriate for a 16-year-old to learn to race with. I would probably try to get something 4 to 5 years old with a moderate amount of mileage and out of warranty, and it seems like the prices are pretty reasonable. I have already gleaned from reading several threads here that it would be best to avoid the 2013 model year, so I would probably be looking for 2014 or newer with more than 50,000 miles and in decent condition. Are there any other particular areas that I should pay attention to when looking at a potential car? Are there any weak spots that would need to be addressed before putting an older car onto the track? How tail happy is it in stock form? I mainly ask that because I would probably replace BOTH the Prius and e30, so this would be his daily also. We have mild winters, but do get occasional snow.
　
I should also mention that I generally do my own work. Are these cars pretty easy to work on without highly specialized tools or a dedicated computer?

I know that's long. Thanks for reading!