Huronlad

Welcome to the club. FQ101 has maintenance instructions for the 450.

A Scanguage or equivalent would be a good investment to help diagnose. Or you may be able to borrow one from someone.

After replacing the passenger rear wheel bearing, had to diagnose a no start. Glad I have a STAR. Isolated to an ignition issue. No previous running issues, so started with checking engine ground. A temporary ground quickly had the engine purring away. A replacement engine ground is about $23 from M-B. The replacement cable appears to be 2 AWG and the OE feels like 8 AWG at best. I will have to get under the car to access where the cable attaches to the engine and I suspect the plastic guard with have to be removed to get to the bolt. Replacing the ground on the 450 was much easier. Making use of the new cable, an alternate bolt location on the top of the engine and jumper cables, I have a temporary solution for a couple of days. Also the secondary air injection pump is in the way to get at the chassis mounting point. So the non functional pump may get the old heave ho.

Rear wheel bearings on order for the 451 and discovered at least one of my rear BRABUS springs has failed. Back to the OE springs in the rear, I guess.

If you go ahead with the Roadster conversion, please keep us informed.

I expect the OP will have to perform a great deal of customizing. Not knowing what the ultimate end goal of this potential project is, if it was me I would go looking for a BRABUS 450 drivetrain, rebuild it, and install that.

The 451 is larger in most respects but shares brake parts. You would have to fit the 451 drive train to the 450 engine cradle.

A bad connection at either the radio or cd player.

If memory serves, there have been several instances of faulty/broken interior temperature sensors causing the A/C to fail to function. The sensor is located in the passenger footwell.

The 451 will shift up at less than 3000 rpm. One of the reasons I drive in manual mode.

With a STAR machine you may be able to set the LEDs as the default DRLs. That may disable the low beams as DRLs.

No negatives. The resonator box limits some of the intake noise.

I went the Barney O route of deleting the resonator box in my 451 and installing a budget hose. Changing air filters is very easy now. https://www.smartcarofamerica.com/threads/low-budget-intake.26781/

This morning just west of Seaforth. I did not pick the best time to clean the windshield.