You can use observables to replace the first search with the following one. It’ll still run but you wont get weird UI behavior. You can also ignore repeated searches with the same params that may occur with observables. I can’t remember the exact observable odd the top of my head.
Also, consider the trackBy part of ngFor. You can replace the need to remove and add entire cards.
I don't know how to access the dealer site in the article, but the consumer site lets one pick multiple makes with the more search options button. The UX doesn't make this obvious that this is the way to do this, but that is a different issue.
If you select the search options button in the Search group box, it brings up a new page. That page has multiple group boxes for selecting separate make/model combinations for a search.