What is the criteria according to which the two different blocks will "know" whether you want to show cars or trucks?
If you want to control this, and have two separate Blocks showing different term-related content, you can create two Blocks but add regular Filters to them, filtering to show content related to either cars or trucks. The add each separate Block where you want them in a theme region.
If you want an automatic solution where a contextual filter does everything, you usually want to show either cars or trucks, but not both on the same page. Contextual filter will "sense" the context, it will recognize something on the page you're currently viewing, and where you placed the Block, and it will pass this context info to your Views, and filter results according to it. This is commonly used to place Blocks on Node pages, where you want to show other content that has been tagged with the same term. For example you're viewing Car1 node, and want the Block to list all the other nodes that have also been tagged with the term "car", so you would see Car2, Car3 etc. Besides the Contextual filter to pull the related content, you will also want the second contextual filter that would exclude the current node from the list, because it doesn't make sense to the visitor to see it there. You will need to adjust Contextual settings when placing the Block in a theme region.
The third option may sound the closest fitting to your description: Create One Block listing all nodes of that type, add the Field for the Taxonomy reference field, and under Format use the Taxonomy reference field to "Grouping field Nr.1". This will list all content but it will be Grouped in clusters based on the "car" or "truck" tags. You can edit the Field and "Exclude from display" because you will see it in the group title. There is no need for Contextual filters here as you want to list everything, you only want it separate into groups. Place the Block in a theme region and adjust visibility...
You can add the same Block to display in Drupal as many times as you want, in the same theme region, or in a different place, but you can't make it behave differently. A Block with a Contextual filter can show different results only if the Context it's surrounded with is different. But if on the same page, the context is the same, and the result will be the same.
BTW the "Vehicle type" is a Taxonomy Vocabulary, and the "car" is a Taxonomy Term.
