i would recommend selling it and buying something not supported by ford.
i've had 3 new bonnets now and i've just noticed my latest bonnet and both wings are going (bonnet has been on less than 12 months) all full part replace and fitted/sprayed by 3rd parties not ford themselves as in the uk...
I had the mustang done years ago cost me like 1500 quid for paint correction, full xpel ultimate and then ceramic coating.
more recently (september) I had the vantage fully done in gyeon matte ppf cost me 2700 for full car + ceramic coating, didn't need paint correction as the paint was...
There are probably loads if you think about it
Renault Megan
Renault Clio
Toyota Yaris GR
Honda Civic Type R
Hyundai i20 N
Mercedes-AMG A45 S
Audi S3
Audi RS3
BMW 1 series (m1 or 135i maybe)
I'm sure I'm missing many out back in the 90's being in the 200+ club was big business but these days...
i have a full set of factory multispokes with brand new pilot sport 4s's on them, if anyone is interested in making a sensible offer for them (bearing in mind over a grand worth of tyres)
if you just want alignment services check your local kwikfit's some of them have full hunter alignment machines and can do all the standard alignment profiles as well as aggressive track based setups.
Modurstang in oxfordshire is your closest good place i would say
gearshift can usually be improved by swapping out the fluid in the box and diff to good oil not the ford standard crap. other people have seen improved shifting with 3rd party shifters and stiffer bushing on the transmission.
i did AFE front and rear roll bars with steeda billet mounts took maybe 15 minutes each end of the car on the drive the front one pulls out via the wheel arch without even having to take the wheels off
not much. make sure engine is nice and hot when you take for test (give it a 30 min drive before going) and drive it hard make sure you get it up into the rev range get it nice and hot clear out all the shit, it'll retest below.
so this was why i went with centri not PD as i wanted a low spot before boost comes on but part of the build was a full custom tune by ortiz performance in the states as I wanted professionals who knew not only centri's but had years on the mustang platform and thousands of cars not just a...
Vortech V3 charger dyno'd at 700 at wheel's with something stupid like 1000nm torque but i don't think its really a super charger problem because it'll still quite happily spin the rear end off boost I think its just the MPSS tyres like to be hot and scrubbed up before they'll actually get traction.
mustang is still the most powerful car i own by a fair margin but its really only driveable on perfectly dry days and even then only on certain roads around here as they're just so bad you can't really touch the throttle.