Reveal the word
Inhale and exhale three times, breathing out smoothly. Move the tongue closer to the bottom of your mouth, leaving it relaxed. With this position, exhale as if you were admiring a beautiful landscape.
Listen to the word car in American English and the word car in Catalan. It may help you to pronounce the vowel [a] uttering car more briefly. Look at this video. Do the same with the word bar in American English and in Catalan. Observe the video.