I have a semi daily use, but also Track Mini.
Its a 2005 R53 with some mods to date.

KW Coilovers
Self modified airbox to the usual specs
Poly front wishbone bushes (Race spec)
R56S Front brake upgrade with Good spec discs and Carbotech XP8's
Braided lines
16" wheels with Firehawk Indy 500 tyres.
25mm Hotchkis rear anti roll bar (mid setting)
Front Strut Brace
Race front seats and Harnesses fitted

What would be the next best few mods to improve track work? Ideally cornering speed and acceleration out.

Handling - Thinking adjustable top mounts to give better camber and cornering speed, would adjustable rear control arms have much effect? Semi Slicks?

Speed - 15% smaller pulley and an intercooler upgrade.

 

For sure a set of camber plates would be your best mod as they would save you so much in tires they would be worth their weight in gold
https://www.waymotorworks.com/vorshl...er-plates.html

Of course a 15% pulley would also be a great mod as it will be the best power bang for the buck.
https://www.waymotorworks.com/wmw-pulley-package.html

also I would recommend an ATI damper as the stock crank pulleys already normally fail, but with track use and the stock one getting hot it would suck to break during a track day loosing you the day and your money for the day. Plus the ATI is a little lighter and dampens so much better it will help the car run better too.
https://www.waymotorworks.com/super-...ulley-r53.html

 

Photos!! You and I are of the same mindset and I'd like to see your seat setup....

 

camber plates up front, and a splitter up front

I like the greene performance camber plates, they let you put in more caster too, mcpherson strut will loose less camber as it turns if there is more caster

I use offset control arm bushings to add +2 degrees caster

 

For those that don't know, Mega72 is an AX Champ here in NC and also tracks. He has some great vids out.