I had a typhoon and it was actually a great vehicle especially since it is a awd. I have had numerous 84 -87 gns/turbo buicks. They are cooler looks wise than a typhoon but they are a very finicky animal and very expensive to mod. After owning gns/turbo buick i find it more enjoyable and profitable to part them out.
I tend to disagree, I find these cars are very responsive to minor modifications. Back in early 1990's I did the $500. ( 1990's money) modifications to my 87 Turbo Regal which I still own. Hot wired stock Fuel pump, 160 thermostat, colder spark plugs, exhaust cut out ,K and N filter, chip for 100 octane, adj. wastegate on stock turbo, stronger valve springs, boost guage, 1 airbag, line lock, and sticky tires Hoosier Dirt Booz. Cool day ran a best of 12.60 108. 21 psi. Suprised more than 1 big block at strip.
Even my current setup is still cheap, long block still stock,(except valve springs) larger injectors, higher volume fuel pump, larger stock location intercooler, larger stock appearing turbo, with cold air behind front bumper, boxed control arms, front sway bar off, 9x28 slicks, 90 10 shocks, transmission redone with stock style convertor, higher stall. Chip for larger injectors and timing for 110 octane 23 psi. Cool day 11.35 115. They are a pretty basic car, just have to be sure sensors and grounds are 100%