Yaris homebrew race car?

[Kiteless]

So next month (July) My Yaris turns 5 years old. I plan on keeping the care another 5 years. It will be LONG since paid off by then. A friend of mine says I should turn it into a track day car. Racing slicks, rims good for racing, even stiffer springs, and a little lower. I could remove the seats, spare tire interior, some of the dash board, radio, replaced the driver and passenger seats with racing seats, carbon hood, aaaaand turbo…

But… Should I bother doing this to a 10 year old Yaris? What kinds of other things should I be looking for? The engine will have about 200K miles on it. Should I have the engine rebuild, or maybe even drop in a new engine? What about the transmission? Would I need a new stronger gearbox? Granted 5 years is a long time from now, but I am mainly just curious to know if anyone has done any of these things, what all they did and how much it cost?

Thanks all,

- Jason