Solar panel mounting on rubber roof

Butyl tape and Self leveling Dicor have a great reputation by the DIY crowd on here along with the RV service industry. They are the go to products for sealing holes, preventing leaks. Your likely to create bigger problems trying to mount to your gutters or side walls than you are mounting with your L brackets right to the roof. That's how the professionals do it. Why would you try something different? Deep Breath and go do a nice job as Mike-uswest describes.