My final ramp ended up being pricier than I anticipated with the added membrane and drainage pipe, but it was still much cheaper than the heavy duty rubber ramps I found on Amazon. I ended up using the recommended substrate in case I needed to remove it for any reason and an aluminum rectangle tube for drainage. After three months, so far so good. Water seems to be draining underneath and I haven’t had to move it for any reason. Not to mention my car no longer bottoms out on the curb. I am satisfied with the investment.