Mark B

Do Not Trust This Dealership

Marshall Mercedes-Benz Preston has given me the worst dealership experience I’ve ever had with any brand. My strong advice: do not use this dealership. My experience has been a sequence of misdiagnosis, poor communication, missing paperwork, and pressure to approve unjustified, expensive work. The fault and first three visits My 2017 Mercedes E220d began showing intermittent warnings that the driver-assist systems were being disabled: • Distronic inoperative • Active Brake Assist functions limited • Lane Keeping Assist inoperative • Blind Spot Assist inoperative The behaviour strongly indicated an intermittent connection: the warnings appeared on a cold start, then cleared after driving for a period. Visit 1 – 21/07/2025 Marshall’s barely listened to the description of the symptoms. I was charged £200 for one hour of diagnostics. They later called to say the car was “fixed” after a software update. Within one mile of leaving the dealership, the fault reappeared. Visit 2 – 12/08/2025 Back it went. More overnight diagnostics. Another £400 for two hours. Again they verbally assured me the car was fixed. And again, within a mile, the fault returned. Visit 3 – 19/08/2025 By now I’d spent £600 on unsuccessful diagnostics. Instead of any ownership of the situation, they presented a £1,500 quote for a replacement Distronic Control Module — without any guarantee it would solve the issue. I asked for a detailed record of the work and findings from the previous visits. They twice promised to send it. Nothing ever arrived. Not once did anyone mention this issue posed MOT or safety risks. In fact, it’s entirely a driver-assist system that can be toggled by the driver and is not part of the vehicle’s core braking system. Service & MOT – November 2025 At my latest service, I was upfront with them: I wanted the long-standing issue fixed but simply couldn’t trust them after repeated failures and £600 already spent. A few hours later, I received a call saying that if they continued with the MOT, the car would fail due to the “Active Brake Assist – functions limited” message. They cited section 1.7 Electronic Braking System (EBS) – Warning Device Shows System Malfunction. This is a misapplication of the rules. The warning device is not malfunctioning. And the EBS in question is a driver-assist, not the car’s actual braking system. I immediately contacted three independent motor trade professionals. All were clear: this warning is not an MOT fail. By this point, it felt very much like the dealership was using the MOT process to pressure me into approving previously refused expensive work. Final thoughts This dealership has wasted my time, cost me money, withheld promised documentation, repeatedly misdiagnosed the fault, and then attempted to leverage the MOT as a tool to force authorisation for costly repairs. I love my Mercedes, but I will not return to Marshall’s and would strongly urge anyone reading this to avoid them. There are excellent independent specialists and better dealer groups. Choose one of them instead.