In case anyone is looking at fitting the Brandrup transparent film bumper protector, I've just done it and it turned out really well. It's almost invisible. The instructions aren't brilliant, much like everything else I've had from Brandrup. Here's my instructions:
1. Only apply at an ambient air temperature of 16C or above.
2. Mix the agent with 300ml of clean water in a clean spray bottle and shake well.
3. Wash and dry the bumper. Remove any tar or other marks if required with an appropriate solution and re-wash and dry the bumper.
4. Liberally coat the top surface and lip of the bumper with agent mixture spray.
5. Peel the backing off the bumper protection film in stages, liberally coating the adhesive side with the agent mixture spray.
6. Position the bumper protection film centrally on the bumper.
7. Whilst holding the film in position, use the included squeegee to smooth the film on the top of the bumper and expel the water, starting from the centre and working out to the edges.
8. After the top is in place with no water or air bubbles, use a hairdryer to soften the bumper protection film (maximum 80C) and use the squeegee to carefully smooth the film over the lip of the bumper, taking great care to expel all bubbles. For this part, it is critical that you start in the centre of the bumper and work the squeegee towards you and then over the lip and down. Then continue with this process, using the hairdryer and squeegee to smooth sections from the centre to one side, then from the centre to the other side. If you get any bubbles trapped, immediately spray more agent solution onto that area and gently peel back the film and reapply using the hairdryer and squeegee. You must take your time with this stage and be careful with the heat of the hairdryer. You want the film warm enough to be flexible enough to wrap neatly around the bumper lip but not so hot as to result in stretching of the film. This is pretty intuitive in practice.
Hope this helps someone.