I have a new to me 2005 S type R . When I start the car and turn the A/C or heater on I get a gas smell , and since the air intake is close to the fuel lines I suspect a leak some where . Any advise on what I should look at first . I bought some dye that I am planning to put in the fuel tank hoping to find where the leak is.

 

First obvious step: Look under the car, especially after driving, if you see somewhere fuel dripping out - maybe even a puddle of fuel.
Obviously, if fuel is indeed leaking, that is a huge fire danger - I suggest that you don't drive that car until you have a fire extinguisher accessible in your car for "quick excess".
Apart from that, I'd start by swapping the fuel filter, which is always a good idea. The brand "WIX" is good.

 

While looking for something else on youtube, I came across this - maybe it helps...:

 

Thanks for the info . I did put it on the lift and removed the driver wheel well liner to inspect the fuel filter , no leaks but I am going to replace the filter before it goes back together . I did look at the fuel lines that are visible didn't see anything . The supercharger and plenum make it hard to see the injectors but that is what I am going to focus on next . I have 3 projects cars going now so I bounce around working on them .

 

I had the same issues a few years ago with my 2005 S Type R. Found out that there was a recall in 2007 for all S Type R's for a faulty fuel tank. With some research I was able to locate documentation that the previous owner complied with the recall and Jaguar fix the problem free of charge. Fast forward about 5 or so years ago and I started smelling gas but no signs of a leak. My mechanic was able to find the leak and it was basically the original 'fix" had worn out and the initial problem had returned. I wish I had contacted Jaguar back then to see if they had any recommendations to fix the leak. That repair cost me over $3400.00! I love that car but I'm smelling gas again and I'm thinking it might be time to take her out back and shoot her. Hope you have better luck with yours.