I have been trying this extension on my website since yesterday. I think this extension does not have several qualities that is expected in a pro/commercial extension. I found the following issues on this version:

1. Only one view (detail view) is available. (in other words, you don't get any option to select various views while adding the component on a page)
2. There is no search module. The only option for search is on the default view. When enabled, it is displayed on every single page, even on the page that displays form to add a car.
3. It is difficult to customize the look/style of the page because the source code is not well structured. For example, the view folder is inside the model folder. The helper program is utilized to display search forms. Tons of nested tables are used for formatting.

Overall, it is good for money and worth buying if you are prepared to learn PHP and CSS.

It works. However, you need to do a little homework before it is production ready. I had the following issues when I installed it.

1. No support/forum links for this extension.
2. Documentation (readme.txt) lacks detail for a new Joomla user. For example I did not the "Custom HTML" is a pre-installed component in Joomla 1.5x.
3. I had to modify the plugin (hpregistration.php) to remain in the registration page when captcha (confirmation code) was incorrect. The existing code throws a warning and registration is not aborted. I simply duplicated the code that is executed when the terms of use check box is not selected.