Your inventory pages are WAYYYY more important than blogs or landing pages. Taking a look at our top 1000 entrances (non-homepage) from Organic Search visitors over last 90-days, inventory pages account for 948 of those entrances. Those inventory pages will build dynamic, updated daily content if done correctly.
Absolutely they will. And they need to be fixed, but I wouldn't fix them and call it a day.
This is why I emphasized the fact that the blog visitors tend to be "in addition to" the inventory visitors.
If I exclude the homepage over 90 days, its about 1/2 used inventory and the rest is divided between service landing pages, vehicle landing pages and contact. I can correlate my conversions to their landing page and it's not uncommon that they landed on one of our landing pages.