I have just bought a Subaru Legacy estate 2.5 petrol awd. 2004 for the snow
Paid cash to stay finance free for a while as now possibly moving house, trying to get a new mortgage will be easier with no other debt.
Dealers name did start with that and finished with park cars.
Biased I know, but 530d takes some beating for combination of comfort, economy, load space, spec and street cred. Lots of excellent ones well within your budget. You know it makes sense; this IS a 5 forum when all's said and done.
Sorry to hear of your troubles.
Reject the car. And quick.
You say the oil has a chemical smell and that may well be an additive but it's more likely due to the DPF being u/s. The EDC is pumping more and more fuel (as it should) into the motor to accommodate a regen that's not happening. This neat diesel will find its way past the rings,washing the bores as it passes and contaminate the engine oil. If left to continue the oil rises in the sump and sooner or later the motor will get into a 'run away' situation where it will basically run on its own oil and destroy itself. You'd have half a chance to catch it since it's a manual but it's not a nice experience if it did happen. The motor will not stop on the key in an run away situation!
If it was to blow up at anytime that would be a get out clause for the the dealer as he's only gonna say misuse on your part.
Return the car and polititly ask for your money back. What with that and the other issues including the tyres the cars clearly not fit for service considering that in the approx 2 months you've had it it's been at the dealer for repairs for approx 1 of those months. At the very least have the repairs done by a firm/garage you trust and feed him the bill. That should include the DPF and associated components,an full oil change and I'd be looking for some decent tyres as well.