I have heard that some Challenger owners have encountered circular shadows in the temperature gauge and the tachometer lenses when the panel is lit up. Unfortunately, this is not due to a bad LED bulb, but a defective electro-luminescent sheet. It's not a heat related issue (like incandescent bulbs) but either material contamination within the EL sheet or degradation to due hot/cold cycles. If you encounter this dreaded problem, you have three options: 1. Take it to the dealer. They will replace the entire IP assembly(list price is $809 plus labor). 2. Take it to an instrument cluster repair shop that will replace the EL-film transformer that's soldered onto the back of the cluster. In PA, InstrumentStore.com, 181 Hills Creek Rd.,Wellsboro PA 16901 (800) 590-2716, will do this work, reasonably, for about $250. There are probably other competent repair shops in other parts of the country. The repair takes about a week. 3. Replace it yourself (for the skilled). You have to remove the driver's side sill trim, plus the upper trim above the sill to access screws for the lower trim panel. There's another one below the start button/fob port as well. Then you have to sharply pull the IP cluster trim panel and then remove the screw that hold the IP cluster to the dash. Next, you have to remove the screws that hold the lens/mask to the cluster. There are three electrical connectors on the back of the cluster you have to unplug to get the cluster out of the dash. The needles have to pulled off the gauges, then the gauge face has to be carefully pulled up (the centers have a heat welded stub). The EL sheet lays underneath the gauge faces . (The openings around the gauge centers are larger than those holes). You can then unplug the connector for the EL sheet. (Note- You could probably get a Charger or Magnum Cluster (maybe even a 300) from a dismantler (check to see if the EL sheet is good), since the basic cluster seems to be a common design and take it apart to transfer the EL sheet into your Challenger cluster).