evening..
1) any tyre place will be able to tell you if its the valve, tyre, or wheel itself that is leaking.. they probably won't even charge to check it out. Or you can check it yourself by mixing up some fairy liquid and water in a spray bottle. Spray it all over the wheel and watch for the bubbles.
2) powder coating is the most durable solution.. but if you want them shiny then a strip down paint/polish or diamond cut is what most wheel refurbishers do. Expect to pay anything from £120 to £300 for all four wheels.
3) radio code will be written in your handbook that came with the car.
4) if the light keeps coming on.. they arent fixing the fault, merely clearing the error codes and resetting the light. There are many things that could cause the light to come on.. the car's ECU will store the fault codes which can be read by vagcom or other diagnostics. VW charge a nice fee to scan those fault codes.. but many members on here have the tools to do that and will gladly do it for free if you're local.
oh yeah.. welcome to the forum
