As the Sterling/Euro exchange rate is so volatile, I've removed the conversions as they get out of date so quickly.

All tickets, including Jahreskartes, are valid for the the calendar year. Note calendar year, not for 12 months, so they expire on 31st December.

A Jahreskarte ('year card') is a season ticket valid for unlimited use by the cardholder within the calendar year.

The Jahreskarte itself is only an identity document. To open the barrier, you get a watch-style transponder:

This is coded with your ID card number, and random checks are made to prevent misuse.

The transponders have a theoretical range of 8cm, but in reality you often have to almost touch the transponder pad, which can be difficult when on your wrist in a car with harnesses. Most of us put it around the gearstick or hang it round our neck to lean out the window with it.

Jahreskarts are also valid only when the Jahreskart holder is driving/riding. They are not valid when you are a passenger, even if you are a passenger in your own car. The transponder is for the driver/rider, not the vehicle. They do sometimes check the photo, and confiscate cards and transponders which are being misused, so it's not adviseable to take chances.

The procedure for buying a Jahreskarte is to turn up with cash or credit card, a passport-sized photo and your passport. At quieter times, they will issue your card immediately; at busier times, they will keep your passport and lend you a temporary 5-lap ticket. Go back 5 laps later and swap your temporary ticket for your passport and Jahreskarte. To renew an existing one, just take your existing card and the dosh. Note that although they have a digital camera there, it isn't always working, so it's best to take your own photo with you just in case.

If you want to get an idea of all-in costs for a weekend trip, for a 'standard' weekend (out Fri, full day Saturday, half-day Sunday, return Sun afternoon/eve) from London by car, the costs look something like this:

• Channel crossing: Varies, but say typically £120
• Petrol en-route: Typically 2 x £60 = £120
• Petrol for the Ring: Say £90
• Bed-and-breakfast per person: £25 per night x 2 = £50
• Food: 2 x dinner, 2 x lunch, food en-route, beer = £100
• 25-lap ticket = £232
• Total = approx £700

Of course, these costs get disguised a bit as you usually pay for the ferry some way in advance, and pay for petrol with cards and thus don't get that bill 'till later.

Once you have your Jahreskarte, the cost per weekend drops to around £500. In terms of Euros, you can use credit and debit cards for petrol, Ring tickets and food (in most places) but you'll want cash for accommodation costs and miscellaneous bits & pieces. It's usually cheapest to get cash at a local cash-machine.

Optional extras available at additional cost include armco repairs, safety car attendance, vehicle recovery, track closure, hospital stays and helicopter rides. I recommend avoiding these. If you can't, then the following price-list may help:

• Base fee for attendance of armco truck: €150
• Removing damaged armco: €10/metre (x2 or x3 or x4 for multiple-height sections)
• Replacement armco: €31/metre (x2 or x3 for double/triple height)
• Removing damaged armco posts: €5.10 each
• Replacing armco post: €39 each
• Safety car attendance: €82 per 30 mins (car + 2 people)
• Circuit closure: €1,350 per hour
• Recovery truck: €190 (inc VAT)
• Hospital stay & air ambulance: Let's just say, do NOT go there without travel insurance! (Though a European Health Card - which replaced the E111 - may cover the hospital bit.)

Everything except the recovery truck is then subject to 19% VAT.

The record armco bill I'm aware of is €15,000. That was a car that managed to flatten a very impressive length of armco between the Quiddlebacher Hohe bridge and the crest on the approach to Flugplatz. But even a minor bump can turn into a surprisingly expensive day out.

You'll find my favourite currency converter here.