How many times in 2017 did Google push to use the YouTube director app? Be careful falling too far for Google’s AMP project.
In terms of changes, direct traffic, business name searches, geo + product location, etc. will not be affected. Only a small fraction of long tail searches may be affected. If you don’t even do custom content this may be less than a tiny change in indexed pages.
However, the speed test is greatly affected by image optimization which is really an image quality degradation choice. We all use the same cloud optimization systems, so what’s left is to chose either fewer images per page or fewer quality (pixel density) images. Additionally, the script optimization problem has to be fixed by each one of the companies providing the scripts to the website provider as they are built.
All these changes come to one choice: how much content, links, maps, etc. do you need per page? Showcase all or reduce and speed up.
You must chose the right balance. But be careful, don’t fall for another Google project that may die by 2018’s end. Remember that Google’s AMP is a global project, and I don’t believe it will affect local automotive sites. Take off unnecessary stuff from your site, but don’t trade quality for speed.