You need a heat gun, a garage and some patience. If you make creases then you failed but any bubbles will and can be fixed. It takes a good two weeks after the initial install to see the bubbles go away by themselves from my experience. If you still have a few then you can heat the spot up the bit and fix it easily. I have used headlight armour brand tail tints and fog light tints to good effect previously on my Liberty. I even got stopped for random check over the car a couple of times and they were just concerned with the tinting on my drivers windows (passed both times). The key is not to go too dark with the tint.

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Funny looking German Subaru