Hi Martin - the Jaguar E-Type is not Digital Plug Ready (DPR) so will require a C7005 Retro-Fit chip soldered in.
A good strategy with the front-engined cars like the E-Type is to attach the chip to the body on one side of the cockpit. This will need some of the cockpit removed and the large cylindrical capacitor on the chip will need to sit just in front of the cockpit. There is room to place the LED between the end of the guide blade and the motor - about 6-8mm behind the end of the guide blade is perfect.
In some of the wider front-engined cars (like the Corvette L88), there is room to fit the chip vertically in the chassis alongside the motor. Be sure to insulate the chip from the metal motor can (I usually tuck my C7005 chip inside a piece of wide diameter heatshrink tubing, but not heated...). I think the E-Type chassis is a little too narrow for the chip to fit in the chassis there, but you could try and it will save modifying the cockpit.