dunno if you have checked out the site
www.streetglow.comfrom the description, gold series:
Each Gold Series undercar kit comes with 2-51" bulbs for the sides, 2-30" bulbs for the front & rear, a powerful 9500V transformer, all necessary mounting hardware, and installation instructions. Each neon bulb is encapsulated in high impact lexan® to withstand the toughest road conditions and elements. Available in nine exotic colors and a no-hassle lifetime warranty (even if it breaks*), making it the #1 choice for Auto-Neon® enthusiasts worldwide.
The Gold Series undercar kit is designed to withstand extreme competition levels. Truely the best undercar kit in the world. Built for the true Auto-Neon® enthusiast.
blue line series:
Each Blue Line Series under car kit comes with 2-48" tubes for the sides, 2-30" tubes for the front and rear, built in transformers in each tube to simplify installation, all necessary installation hardware, instructions and a no hassle lifetime warranty (excludes breakage).
Each neon bulb is encapsulated in high impact Lexan® to withstand the toughest road conditions and elements. Available in 9 exotic colors. The Blue Line Series was designed for the do it yourselfer and hobbiest in mind. Quick installation and consumer friendly pricing make this a winner for any Auto-Neon® entusiast.
Blue Line Series tubes are not limited to undercar application they are also great for truck bed rails,engine compartment,anywhere imaginable (simple 2 wire installation) basically any application which requires a longer lighting configuration.
what i see is that the gold series tubes are just a few inches longer, also the gold series does not have a built in transformer with each tube, unlike the blue line series.
here is something to consider...i just ordered LED insterad of neon, seems to me like it is about 10$ more expensive, but does not get as hot, does not get hot spots, burns brighter, and lasts longer...just something to consider.
btw, i ordered plasma glow. just dont buy from thier website (www.plasmaglow.com) everything is 2X as much on thier site. do like bizprice.com or something and it compares prives from 100's of online stores, so you can find the cheapest place.