Battery OPTIMA or OEM Audi

Bought my Red Top @ Costco for $105.95. Fits like a glove

Ah, but the Red Top fits in the TDI without problems. About $109 at Costco.

I have the stock VW battery under the hood and an optima yellow top in the trunk with a 5 farad cap as well, now Im doing DB drags, and I also use my car as a daily driver, I have yet to see a single bit of strain on my electrical system and belive me I have two Autometer volt guages just to be safe for monitoring.

Ran a dual battery setup in my S4... was easy. Ran a PAC relay from the main battery to the rear setup with a battery isolater. Battery charged when the stereo was on, and stereo was only powered by the Optima yellow top in the trunk.

I've had an Optima ever since and never a problem...

I have a blue top (couldn't find yellow locally) and I love it. Damn battery box doesn't though (had to chop it up and piece it back together to make the battery fit).

Optima batteries are some of the best batteries you can buy. THey are gel cell batteries, not like a conventional dry cell like in your car now. They are also deep cycle batteries, sealed so they never leak, and have 2 sets of battery terminals. They are practically indestructible.

My battery died a hacking death with my stereo system and HIDs after 2 years. I wanted a red or yellow top Optima, but they don't fit without modification. In a pinch I got an 800cca direct replacement, can't remember the brand, too lazy to look.

I have had nothing but problems with optimas and I am far from the only one. Go with either an Odyssey or a walmart brand yellow top. I had one sitting around for 6 months hooked up to a non running vehicle. Tossed it into my gf's bronco to fire it up one day and it started right up. Also, I run those in my diesel, and I left the interior light and cargo light for over 12 hrs. Got in and she fired right up.

FYI New optimas are the suck. Good luck though.