As one of its daily deals, All4Cellular offers the Kensington SoundWave Sound Amplifying Car Mount for iPhone 3G / 4 / 4S, model no. K39259US, for $12.99 plus $2 for shipping. That's the lowest total price we could find by $20, although we saw a similar model for $3 less after a rebate last winter. This mount features an amp that doubles the volume of your iPhone's internal speaker. Deal ends today.