That's the Battery I just put in my Solstice, removed the previous owners wall mart battery that seemed to be leaking causing a corrosion issue to start on the inside of the front fender, and the top of the battery tray.
Interesting that this is one thing that seems to be easier to change on a Mallet conversion, as the power steering reservoir is not located above the battery now. I also am using this opportunity to replace the slightly cracked inner fenders, and remove the ECM so it can be sent out to fix the cruise control issue inherent with the early conversions.
While I did find the battery a bit of a pain to change, I have owned cars that it was worse. I had a 70's Ford that you almost had to remove the front fender to get the battery out. You could see it, get all the hardware loose, but just could not get it out of the position it was in without loosening either the front fender or the radiator core support. Removing the front fender of a Solstice is not a difficult job Provided you can open the door all the way to get to the 1 bolt mounted at the rear of the fender.
Certified Pontaholic & Former Jet Mech
1969 Firebird Sprint 301 OHC-6, T-5
1971 Catalina Freeway Enforcer 455
1973 Lemans Safari 400 4-speed
1977 Astre Formula 215 V-8 T-5
1978 Sunbird Safari 231 V-6 2004R
1978 Catalina Safari Soon to have a Pontiac 400 4bb
2006 Mallet Solstice LS2 6-speed Manual
2009 G8 GT