noetus

Don't take my word for it that your new lights will pass MOT. That is just theoretical knowledge, never tested by me (Though car has gone through two German TÜV tests without issue.) Wouter at Retrofit should be able to give you a definitive answer before you go to the trouble of fitting them. I don't think he'd ship to the UK (or legally be able to without labelling them as off-road only) if they wouldn't, but best to be sure. It's funny that over on camper van and caravan forums, where you regularly see people discussing what to do about headlamps with vehicles they regularly take to/from the continent, I've never seen the suggest to fit US style projectors/reflectors. As a solution to the problem, it's a pretty neat one. Note that MOT testing procedure on headlights recently changed https://mattersoftesting.blog.gov.uk/the-mot-headlamp-aim-test-is-changing/

Right now, Lyon. I'm a Brit by origin, but usually live in Budapest, at the moment in Lyon for a year. The A4 was bought in Berlin 4 years ago, where I think it had spent most of its life in quiet residence. Since then, I've taken it to a total of I think 20 countries, from Greece and Albania (fun roads) and Romania, to Belgium and England at the other end. Some of it towing a trailer. Trips planned this year to Scotland, and Romania again. Possibly Greece again, too. Never caused an accident (touch wood), but I've been hit by other cars and motorcycles several times (and a truck) in Greece, Hungary, and France, and attempts to break in twice (car fended the vandals off both times with its strengthened glass; they were unable to gain entry despite very forceful attempts). France is the worst, to be honest. Both for the driving and the two attempted break-ins in the first two months, which never happened during three years in Greece, Romania, Albania, Macedonia, Serbia, Montenegro, Kosovo, Bosnia, Hungary, Slovakia, Slovenia, and Croatia! Possible trips for the future: Turkey, Ukraine, Russia!

Consider upgrading to xenon or bi-xenon from Retrofit Lab: https://www.retrofitlab.com/ You can use your original light housings (no need to replace them), you'll enjoy vastly improved light output, and you'll get the US-style 'flat' cutoffs that are legal in both the UK and Germany (and should pass the MOT/TÜV in either place). (I have nothing to do with Retrofit Lab; am just a happy customer of theirs.)

I was in the same boat, then discovered that there are owners workshop manuals published in Germany that cover the 2.5 TDI and Quattro variants: http://www.originalanleitungen.de/automobilia/audi/audi-a4-s4/audi-a4-b6-b7 Of course, you have to be able to read German

My 2.5 TDI car occasionally misfires at idle, especially when cold and just started up, with no report codes.

Good work! Have owned a 2003 2.5 TDI quattro sport (180 hp engine) for 4 years, with no major issues. Love the car!

Once you've figured out which housings to get, consider upgrading to bi-xenons from Retrofit Lab: https://www.retrofitlab.com/ My car already had the factory bi-xenons so I didn't have to do the retrofit, I just replaced the projectors from ones they supplied at Retrofit. The difference is amazing; with new bulbs (now 3 years old) my 13 year old car can compete with recent Audis and BMWs for light output. Another advantage with the aftermaket bi-xenons I have is that they have the US style 'flat' cut-off, not the EU style slanty one. This means they are legal in both the UK and on the continent. No silly stick-on converters when I drive back and forth, and theoretically the car should pass the MOT in the UK as easily as the TÜV in Germany with no modifications whatsoever. (I can confirm the car did pass the TÜV test in Germany with these new projectors, where the car is registered.)

I have owned a 2003 Quattro Avant 2.5 TDI (180hp) for four years, third owner. Ḷove the car, have done a fair bit of maintenance and upgrades on it. A lot of people recommend staying away from the 2.5 TDI engine (soft cams, timing belt going out), but haven't had any issues with it so far (touch wood). I like the engine's driving characteristics. And it hasn't thrown a code in the four years I've had it, now at 196 k miles. Mainly I have had to deal with worn suspension bits, replacing control arms, that sort of thing. Now the dampers are beginning to go finally and I am looking to replace the entire suspension with a Bilstein B12 Pro kit. I stupidly broke the glovebox hing and the armrest hinge and hard to replace both, watch out for that! Driver door electric went about 3 years ago, had to replace that. Rear wiper seized due to leaking washer fluid, it's common problem, so check for leaks in the tailgate. Any specific questions you might have?