Suggestions to improve the E2E UI/UX of my SPA [on hold]

I am a front-end web developer who's fairly new to design and UX. I have built a web application using Angular 4, Angular Material, and Angular Flex-Layout. However, I haven't assessed the UI/UX portion of it, and over 1300 hours I have become too familiar to offer myself any input with the user experience, and it is not ready for beta testing. I am going to use my current project as a platform to commence my journey with UI/UX. This site is mobile first.

The URL: http://34.209.2.59

I am looking for feedback regarding the current end to end user experience,and suggestions to improve:

Custom Car Configuration Tool: http://34.209.2.59/carbuilder/401676570 Details: http://34.209.2.59/details/401676570

These are conversion points, and are of most importance. UX is very important here.

How can I improve it?

Makes: http://34.209.2.59/makes

This is first point of conversion.

How can the grid be improved?

Search : http://34.209.2.59/search

Where would be a better place for filters?

What are some "custom" dialogs that work?