Some tips required from the Left hand driver/owners.
Discussion
It's not difficult to get used to. Maybe the first couple of days/weeks and that's it. The fact that the M3 has the dog leg gearbox is more to contend with at the same time as getting used to the LHD.
Only issues are car park barriers, drive throughs and overtaking. I've never taken my M3 into that sort of car park so that's one issue sorted, rarely get a McDonalds but if we did we'd eat in and look at it from the window. As for overtaking, you don't spend your journeys overtaking so it's not a worry and when you do overtake you just make sure you take extra care.
I've only done 200 miles in mine in the last 2 years but I can jump in that and it's second nature.
Only issues are car park barriers, drive throughs and overtaking. I've never taken my M3 into that sort of car park so that's one issue sorted, rarely get a McDonalds but if we did we'd eat in and look at it from the window. As for overtaking, you don't spend your journeys overtaking so it's not a worry and when you do overtake you just make sure you take extra care.
I've only done 200 miles in mine in the last 2 years but I can jump in that and it's second nature.
Viper said:
hang back from the car infront for a better view and use the power to overtake
Edit: ewenm beat me to it.Beware the blind spot on the right. When in the UK, I angle the passenger door mirror further away from the body of the car to cover more of the offside lanes.
Other than that and toll booths/car parks, it's really not a problem.
Apparently, some people use litter pickers for the latter:

'punt
Edited by Cunning Punt on Tuesday 22 November 20:30
Maximum Bobs said:
Passengers usually have a look of fear on their faces.
You will get used to using this as a gauge of how safe it is to overtake!Only joking, they haven't got a clue how much power you have so go for it anyway!
I've been driving LHDs for over 30 years it's never really bothered me, just get your passenger to pay if you must use McD's, leave a bigger gap before overtaking, enjoy!
As above, I'm used to it so can switch at a moment's notice. Sometimes hard to see past a large vehicle in front but I find most drivers sit more towards the whitel line whereas in a LHD you use the kerb as a reference so can often see straight up the inside of the vehicle in front. It's as broad as it's long really. Tolls are a nuisance but it keeps you fit.
Been driving lhd for ten years or so. Go for a couple of hour drive on a mixture of roads and by the time you've done that you should be ok with it.
For me parking has never been an issue. It's not a daily driver so wouldn't ever end up in that kind car park. As said already over taking isn't that much of an issue. Tolls like the M6 or Dartford crossing have the option of tags.
One thing to add that hasn't been said is driving on busy motorways. I find this is better in a lhd as everybody in front tends to drive towards the right of the lane to improve their view. In lhd you can drive to the left of a lane and see way further.
If you go abroad for hols, Le Mans etc you are of course then driving in the correct position I find it takes a day or so to get used to exactly where the car is in the road when I switch from driving in the uk to Europe but then the car is quite wide.
Insurance may be weighted against you at first if you haven't driven a lhd before.
Don't let it put you off, it's not such a big deal
For me parking has never been an issue. It's not a daily driver so wouldn't ever end up in that kind car park. As said already over taking isn't that much of an issue. Tolls like the M6 or Dartford crossing have the option of tags.
One thing to add that hasn't been said is driving on busy motorways. I find this is better in a lhd as everybody in front tends to drive towards the right of the lane to improve their view. In lhd you can drive to the left of a lane and see way further.
If you go abroad for hols, Le Mans etc you are of course then driving in the correct position I find it takes a day or so to get used to exactly where the car is in the road when I switch from driving in the uk to Europe but then the car is quite wide.
Insurance may be weighted against you at first if you haven't driven a lhd before.
Don't let it put you off, it's not such a big deal
No problems whatsoever. It's just a conspiracy theory. 
I only made a slight mistake once. I filled up and went to get in the wrong side, that's it!
Even if it was an issue.....The fact that you are driving an E30 M3......Everything else pales into insignificance. (Honest).
I'm not being flippant at all, it's just not an issue. As said above overtaking, you look up the inside if it's tight etc.
It's actually better in some ways, for example, parking at the side of the road. (You are next to the kerb).

I only made a slight mistake once. I filled up and went to get in the wrong side, that's it!
Even if it was an issue.....The fact that you are driving an E30 M3......Everything else pales into insignificance. (Honest).
I'm not being flippant at all, it's just not an issue. As said above overtaking, you look up the inside if it's tight etc.
It's actually better in some ways, for example, parking at the side of the road. (You are next to the kerb).
Basil Brush said:
It's funny when you offer people lifts and you both end up on the same side of the car with the passenger looking a bit confused.
but you do feel a right prick when not concentrating you walk over to the car and in front of a number of people get in the passenger side only to find no steering wheel. Gassing Station | General Gassing | Top of Page | What's New | My Stuff



)
You can use the view down the inside too to help with overtakes.
