Well, aftermarket companies have improved the breed immensely, like they have for VW based aero engines, which is essentially doing Lycoming's development work for them. The car racing industry has passed it's technology along to ordinary cars and recoups the huge development costs that way. As for certification, the FAA and EASA have effectively ceded certification to the big manufacturers,as we all know from Boeing's current miseries. EASA started off by charging crazy money to manufacturers for even the simplest of tests and /or modifications until it was realised that such costs were stifling development and manufacturers were taking their new aircraft or subsytems or OEM parts to the FAA for original certification. EASA at least had the grace to admit that they over-regulated from the early days and have rowed back a lot and now leave more to the manufacturer than before. as for aero engine numbers versus automotive engine numbers, well, obviously auto numbers will always win but when you see the many thousands of Rotax, Robin and Jabiru aero engines out there, and more new types coming down the pipeline,clearly designers are willing to take the plunge and bring out decent engines with modern technology as standard. Forget 1930s magnetos, heavy alternators, heavy starter motors. People want their aero engines to be as reliable and forgettable as their car engines are.