Hybrid is never worth it. If you drive an average 15K miles per year then a hybrid will only save you about $55 per month in gas. Assuming the hybrid gets 45mpg and a normal car get 30mpg. A diesel TDI can beat a hybrid. It will take you 90 months to recoup the $5K, by then a new battery again. It is a zero sum game.

$5K is a lot of money to invest in a car at this late game. If I were you I would check eBay for used one when the car is wrecked, then install it yourself. I seem to read somewhere that Prius battery is quite reliable. There are still gen1 or 2 Prius on the road with original battery.

Good luck.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.