I am supportive of this idea, especially for the possibility of custom honk sounds, but also agree with Kiwi's point about using them in the I/O pack. I assure you that I will avoid that, and will also alter Acclaim F1 to use the default sound again.
As a side note, I strongly disagree with it being one of the worst decisions, as we've had quite a lot of fun with it since it was implemented, especially in All's Fair 5. Although I always endorse stock-like content, not all custom content should have to follow that style. Additionally, it turned out to be extremely useful for the Clockworks pack
and Mladen's real cars pack
. It will also come in handy whenever I end up releasing a pack out of real R/C cars, as I plan on using more realistic R/C engine sounds for them.