Turbo Timers

Paul, If you are turning engine off immediately, a lot will depend on how hard you have been going prior to stopping. Restarting immediately should lubricate turbo bearings before they dry out. Steady cruising round the 'burbs shouldn't do any damage, but traffic light drags, towing or heavy pulling in hilly terrain will require up 2-3 mins idle. Hot weather increases idle time, because vehicle is working harder, and under bonnet temps will be higher.
I reckon they are worthwhile, cheaper than a turbo rebuild. If you do as in "3", then it is illegal(got to get caught first) to leave the vehicle unattended while it is running. Also run risk of it rolling away, if your handbrake isn't too good. However I've been guilty of this many times.
Can install them easily, just disconnect the correct plug, and fit the leads on timer in line, but you need to be a contortionist to get under the dash.
Make sure you clean off any Armourall off the dash before sticking the controller in your desired position. Catch you later...

A turbo can spin on for quite some after you switch the car off IF you have been using the throttle to the extremes and creating a lot of boost. Normally if you have been just country driving or just cruising around the city a turbo should not be spinning too fast, so by the time you have slowed down, stopped and turned the car off it should have settled just fine.

If you have been thrashing it ( as such ), i would wait a minute after you have stopped but if normal driving has occurred since thrash just go back to the first procedure.

I have owned quite a few turbo petrol cars from new and NONE of them has ever come from the factory with a timer because it is against the law to leave your car running unattended even if it is locked.

A turbo timer is good if you dont wanna sit in the car for a minute on a warm down after mounting a huge sand dune.

And they are easily installed and cost about $120 for a good one with heaps of options.

Check with your insurance company, some wont allow Turbo timers...

I'd recommend the turbo timer. I have one on the troopy, very easy to install.