the guy i bought my st205 had an intermittent issue develop where the clutch would stick down, i cant remember what happened exactly but maybe it was worse in the cold, either the master or slave ended up being replaced which sorted it.
my doors are tottally rotten lol, there is pretty much nothing for the bottom cm, this is my second gen 6 celica and the last one had the same problem. at some point they will get replaced as the rest of the car is fine, bar peeling laquer, its in need of a respray.
recently had an mot and found the fuel pipes were correded on the fuel pump bracket, i was only getting about 26mpg, now its more like 30+, didnt even smell fuel as it was leaking only when running, apparently is a reasonably common issue.
another thing worth checking is the state of the bushes on the gearshift linkage, on top of the gearbox, i was getting some crunching changing gears and although syncro's going isnt uncommon it was more down to one of the bushes having split, easy and quick fix. diff mount is another common thing to go.
Mine had the live sound system but it broke not long after i bought the car so i'ts all been junked, not a bad system but nowhere near as good as just putting in your own aftermarket setup.
I have blitz ecu on mine, makes a nice difference the engine feels better towards the top of the revs, planning on fixing it at 1.1bar although tbh with just the blitz ecu, blitz exhaust/hks filter it is quick enough for me now. got some other nice bits on it like original trd carbon raiser blocks ( i say nice, there really faded ), and trd discs/pads up front, and trd bronze forged alloys, light at 5.7kg a wheel. 300bhp is where i'm aiming and i'll be more than happy with that, it should be almost there as it is.
is your car lowered? looks like it might be from the side on shot.