High value domain as e-commerce web site or funnel site.

I own several great high value domain names such as:
racingseats dot com
verticallambodoors dot com
sprintbooster2 dot com

I have developed each of these web sites.

However, I question whether the best way to profit will be to spread my efforts across each of these multiple domains, or to group what I'm selling into broad categories with a single site, and use the domains in another way. For example, the above domains can be classified as web sites for automotive performance parts. So let's say I focused my efforts on building a really great ecommerce site for drautomotive dot com (another domain I own).

How then should I utilize the other domains to best extract their value. I can think of the following options:

1) Leave the domains as they are, and have them be stand-alone e-commerce sites
2) Have the domain names redirect to a landing page for the particular category of product within my performance web site
3) Have the domain names as info sites / blogs that then link back to the landing page for a particular category of product within my performance web site

I am thinking in terms of SEO and whether I'd be wasting great domains such as racingseats dot com by merely making it a blog. Also, I don't know how Google would score be if I redirected racingseats dot com to a landing page at drautomotive dot com.

I would appreciate any help on this matter as it is architecturally an important decision for my efforts.