Without a question! Seeking a used BMW engine with minimal miles and meticulous maintenance records should be your top priority. Keep an eye out for engines from cars with a good track record of reliability, like the BMW 3 Series. Engines with a history of overheating should be avoided, and make sure to look for signs of regular maintenance. Dealing only with reliable suppliers, like recycling facilities approved by BMW or trustworthy online marketplaces, is your best bet. A warranty should be obtained, and you should consider having a professional inspection done. Do your homework and cross-reference the VIN numbers to obtain precise information.