Refreshing suspension and mounts on a 2013
 

My 2013 BRZ is over 130,000 miles, pretty much no other mods than fixes to my drivetrain. Still on 215 size tires. Over the last couple years I've worked on fixing drivetrain lash and other worn components and its gotten to the point where I can tell I have a lot of parts to replace, and would like to open up discussion on the subject of possibly restoring drivetrain, making the car nice to drive like when it was new, improving some things but not going "full race" through all of it.

I put in the "positive shift kit" and "positive traction kit", whiteline and perrin parts, and noticed that the whole package of stiffening the mounts was great for making the car getting off the line with a lot less fuss, and made shifts crisp. At the same time, the stiffness makes the car feel not as playful. Also, my front end feels soft, unmatched with the stiffness of the rear.

I probably need to replace control arms/bushing/ball joints next. And find a newer model 86 shocks and stuts for sale from the community.

If you were to undertake restoring your high mileage car, what route would you take. If money was no object, would it be worth it to replace the rear subframe?

I think you've got the right idea so far. Whenever I have had to refresh a 10 year+ car its always the soft bits that need replacing first.

Motor mounts, suspension bushings, and most likely engine seals. A lot of this is a pain in the ass to repair/replace without proper tools. It might be easier for you to source newer parts of salvaged cars and replace entire systems instead.