There's a playground in the southeast of the first island, due east of the Pay'n'Spray. Take a car there and just do what's shown in the video, drive the car into the centre pole of the swings and see what happens! You might have to try a few times before it works.Sweet jesus! Where exatcly on the map is that?
BTW, there's a way you can prevent Niko from flying through the windscreen...
Does this work with bikes?
Instead of going forward into the swings, reverse into them, Niko won't go through the windscreen if you do that.