[TYPO3-mvc] findByUid causes an enableFields() issue

[Sebastian Gebhard]

Hi *,

i have a CarRepository in which I have this method:

function findCars(){
	$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery('uid', 
'tx_autoadmin_domain_model_car', 'upload = 4', '', '',25);
	while($car=$GLOBALS['TYPO3_DB']->sql_fetch_assoc($res)){
		$cars[] = $this->findByUid($car['uid']);
	}
	return $cars;
}

Right now it's pretty plain, but I want to implement several filters and 
search features with this method.

Since I set findByUid into the code, the output is the following:

"NO entry in the $TCA-array for the table "". This means that the 
function enableFields() is called with an invalid table name as argument."

Somehow at any place a table name seems to be missing.
This application works has its own backend module yet which also lists, 
manipilates etc the records, and it works well in TYPO3 list module, so 
I guess there's no TCA missconfiguration.

Where should i start to search?