Have you tried running a RMS high speed motor in your Carrera D124 cars yet? You should try one or two first and see what you think. Here's a link to them on the Professor Motor site:
http://www.professormotor.com/product-p/rms1000.htmThe conversion couldn't be simpler- just remove the Carrera motor and unsolder the Carrera wiring harness. Remove the Carrera pinion and install on the RMS motor. Drop the motor in place and resolder the wiring harness. All bolts and connections are compatible with the OEM Carrera motors. No chassis modifications required. Compatible with analog (12-16 v) and digital (Carrera D132) power supplies. All that needs to be done is transfer the pinion and solder the wiring harness onto the motor. The motor bracket holds it in place perfectly. The RMS motor is "rated" at 12 volts, however it will accept up to 24 volts without melting down. If it is to be run on the 18 volt Carrera wall packs look out, it's too much! Even with the softest and stickiest urethane tires, 18 volts is too much. You will be able to run 4 cars with magnets without any problems. You won't need any adapter or aftermarket motor pod to make this work. Even without attaching the motor pod screws and they fit and mesh and work perfectly. This motor is your best choice for using the standard 12-14 volt power pack/transformer for your 1/24 cars. No longer do you need to purchase an aftermarket power supply to run your Exclusiv or D124 cars. The motor shaft is standard 2mm so it will accept any pinion you choose. Both Slot.it and Scalextric pinions can be used with no problems, and many standard Carrera pinions as well. Keep in mind Carrera's own Tuning motor rated 24K rpm at 18 volts, this motor is 30K rpm at 12 volts. It's more than twice as fast. But you will NEVER run it that fast. If you are running D124 you should turn the power down to 40-50% and this motor still provides amazing torque for drifting through turns, magnets or no magnets. It will work with Exclusiv cars also.