Finally got pics uploaded of my audio upgrade.
Kenwood DoubleDin Navigation & DVD player in custom-fabricated dash
Focal Polyglass 100VRS 4" Components up front
Focal 5.25" Woofers from 130VRS components
Alpine Type R Shallow 12" Subwoofer
Another view of the sub / enclosure
All powered by a trunk-mounted Alpine PDX amp
Total system weight = just under 37 pounds
I'm not sure what the original Lotus factory stereo + 4 speakers weighs, but subtract this from 37 pounds and you'll have the total net added weight for my audio system.
1 click of seat travel lost. Subwoofer does not hit the back of the seat, even on full cone excursion.
System power: 100WRMS x 4 for each of the dash and rear speakers, 500WRMS x 1 to the Subwoofer.