Should I just ignore the warning light?

HELPDESK:Answering all your motoring queries

From TM: As a one-time owner of a BMW M3 during the boom, I long for something similar – even if the finances won’t allow it. Understanding that I am stilla true petrolhead at heart but with a much smaller wallet, what are your suggestions for an affordable runabout? I’ve got about €35,000 to spend and don’t want a diesel.

This feels like a hospital pass, for persuading a former M3 owner to accept the more mundane world of motoring the rest of us reside in is a thankless task. With €30,000 you could pick up an old M3, but I guess you also need to consider running costs, which are going to be hefty for such a car.

My humble suggestions would be that you look to the hot hatch market. The new VW Golf R is a cracking good car but is priced at just under €50,000. It’s been on the market for a few months now and if you wait until next year you might get a better deal on a 2011 demo version – or one imported from the UK – but it’s unlikely to be enough to hit your figures. The Golf GTi is still undoubtedly your best bet for the money but if it’s raw passion you’re after then the next generation Ford Focus ST might be worth waiting for. Ultimately it’s going to mean a step down but I get the feeling you’ve already accepted that and are ready to move on. If you want to buy in January then the VW Golf GTi is probably the best bet.

From JP: My 2008 BMW 5 Series diesel is showing the message “particle filter” on the in-car system. One dealer tells me it will cost €2,000 to change, and another says there is no need to replace it, as they can just switch off the message. Any idea regarding the proper option to take?

A particle filter will not cause instant problems but they do get blocked up over time, particularly if you are doing low mileage in urban conditions. It’s likely to become an increasingly common problem as the majority of Irish buyers flock to diesel models.

We contacted BMW’s national technical manager who said that, while it’s difficult to definitively comment as there is no mention of what the mileage is on the car, or if the engine is running well, he suggests you bring it to your favoured BMW dealer and ensure they carry out a full diagnosis with their official equipment.

“Depending on the condition of the DPF, they can check the exhaust back pressure and, depending on the condition, carry out a forced regeneration if necessary. Either way, they will diagnose and assess the situation.” Clearly if there is a problem then simply switching off the warning light is probably not the smartest solution.