Just wondering if anybody has some good methods to fix the roof sagging and removing old dodgy tint?

Thumb tacts :P. Get it relined - cost about $50- $100, or glue it with this special glue. tint i dunno.
Also i cant do that photo chop of your car, the quality is too poor and it's black so it just looks like a silver circle :(.

tint places STEAM off old tint - its a bugger of a job but they generally charge 80-100 bucks for it - which compared to the mess of doing it yourself, is a bargain.

if u are going to retint the car let the tinters take it off they do it for like $50-$100
also you need to take the car to retrimmer to do the roof , just as some info , most cars that have air conditioning especialy magnas are prone to the roof lining coming off if the windows are open and you are driving above 100klm per hour , very common on the first gen

hope this helps norm

Spray water onto the window (with a spray bottle) and cover with a black plastic bag. Tape the edges so water doesn't damage the interior.

Leave in sun on a HOT (Perth hot AKA 36-40C) day for at least four hours.

Peel off tint and scrap what little excess there is.

Clean off glue with some good window cleaner.